diff --git a/.c8rc.json b/.c8rc.json
index 1f371e0..f0583ad 100644
--- a/.c8rc.json
+++ b/.c8rc.json
@@ -4,7 +4,8 @@
     "scripts/cli-args.mjs",
     "scripts/build-diff-data.mjs",
     "scripts/generate-summaries.mjs",
-    "scripts/present.mjs"
+    "scripts/present.mjs",
+    "scripts/serve-built.mjs"
   ],
   "reporter": [
     "text",
diff --git a/.github/workflows/product-gate.yml b/.github/workflows/product-gate.yml
index 981e774..b6fbd74 100644
--- a/.github/workflows/product-gate.yml
+++ b/.github/workflows/product-gate.yml
@@ -17,12 +17,14 @@ jobs:
     steps:
       - name: Check out repository
         uses: actions/checkout@v6
+      - name: Enable the pinned pnpm version
+        run: corepack enable
       - name: Set up Node
         uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
-      - name: Enable the pinned pnpm version
-        run: corepack enable
+          cache: pnpm
+          cache-dependency-path: pnpm-lock.yaml
       - name: Install lockfile dependencies
         run: pnpm install --frozen-lockfile
       - name: Run product gate
diff --git a/.github/workflows/test-lanes.yml b/.github/workflows/test-lanes.yml
index 7f98bd2..f7f2127 100644
--- a/.github/workflows/test-lanes.yml
+++ b/.github/workflows/test-lanes.yml
@@ -20,14 +20,18 @@ jobs:
     steps:
       - name: Check out repository
         uses: actions/checkout@v6
+      - name: Enable the pinned pnpm version
+        run: corepack enable
       - name: Set up Node
         uses: actions/setup-node@v6
         with:
           node-version: 22.13.0
+          cache: pnpm
+          cache-dependency-path: pnpm-lock.yaml
       - name: Install dependencies
-        run: corepack pnpm install --frozen-lockfile
+        run: pnpm install --frozen-lockfile
       - name: Run fast unit tests
-        run: corepack pnpm run test:unit
+        run: pnpm run test:unit
 
   integration:
     if: github.event_name != 'schedule'
@@ -35,14 +39,18 @@ jobs:
     steps:
       - name: Check out repository
         uses: actions/checkout@v6
+      - name: Enable the pinned pnpm version
+        run: corepack enable
       - name: Set up Node
         uses: actions/setup-node@v6
         with:
           node-version: 22.13.0
+          cache: pnpm
+          cache-dependency-path: pnpm-lock.yaml
       - name: Install dependencies
-        run: corepack pnpm install --frozen-lockfile
+        run: pnpm install --frozen-lockfile
       - name: Run Git and server tests
-        run: corepack pnpm run test:integration
+        run: pnpm run test:integration
 
   coverage:
     if: github.event_name != 'schedule'
@@ -50,14 +58,18 @@ jobs:
     steps:
       - name: Check out repository
         uses: actions/checkout@v6
+      - name: Enable the pinned pnpm version
+        run: corepack enable
       - name: Set up Node
         uses: actions/setup-node@v6
         with:
           node-version: 22.13.0
+          cache: pnpm
+          cache-dependency-path: pnpm-lock.yaml
       - name: Install dependencies
-        run: corepack pnpm install --frozen-lockfile
+        run: pnpm install --frozen-lockfile
       - name: Check core coverage
-        run: corepack pnpm run test:coverage
+        run: pnpm run test:coverage
       - name: Upload coverage report
         if: always()
         uses: actions/upload-artifact@v6
@@ -72,16 +84,20 @@ jobs:
     steps:
       - name: Check out repository
         uses: actions/checkout@v6
+      - name: Enable the pinned pnpm version
+        run: corepack enable
       - name: Set up Node
         uses: actions/setup-node@v6
         with:
           node-version: 22.13.0
+          cache: pnpm
+          cache-dependency-path: pnpm-lock.yaml
       - name: Install dependencies
-        run: corepack pnpm install --frozen-lockfile
+        run: pnpm install --frozen-lockfile
       - name: Install browser system packages
         run: npx playwright install --with-deps chromium
       - name: Run the browser journey
-        run: corepack pnpm run test:browser
+        run: pnpm run test:browser
 
   platform:
     if: github.event_name != 'pull_request'
@@ -95,11 +111,15 @@ jobs:
     steps:
       - name: Check out repository
         uses: actions/checkout@v6
+      - name: Enable the pinned pnpm version
+        run: corepack enable
       - name: Set up Node
         uses: actions/setup-node@v6
         with:
           node-version: 22.13.0
+          cache: pnpm
+          cache-dependency-path: pnpm-lock.yaml
       - name: Install dependencies
-        run: corepack pnpm install --frozen-lockfile
+        run: pnpm install --frozen-lockfile
       - name: Check host shell assumptions
-        run: corepack pnpm run test:platform
+        run: pnpm run test:platform
diff --git a/PRODUCT.md b/PRODUCT.md
index c5bf66b..b4bd336 100644
--- a/PRODUCT.md
+++ b/PRODUCT.md
@@ -28,7 +28,10 @@ Developers run `npx diffsplain` in a Git checkout. With no arguments, it compare
 - Compare the current checkout with its default branch when no target is passed.
 - Accept local paths, Git URLs, and GitHub `owner/name` repo names.
 - Report local dependency paths, versions, and readiness with `diffsplain doctor`.
-- Try Codex, Claude, Copilot, Cursor, then OpenCode when no agent is chosen.
+- Try Codex, Claude, Copilot, then OpenCode when no agent is chosen. Cursor
+  detection does not mean support: Diffsplain detects it only so it can report
+  that Cursor is unsupported. It has no supported read-only, no-network,
+  no-tool mode, so it cannot generate notes.
 - Show tracked and untracked worktree changes, exact local ranges, and remote branches as secondary targets.
 - Present full or shortened unified diffs, including binary-file metadata.
 - Pair the whole change and each file with agent-written summaries, reasons, details, and risks.
diff --git a/app/page.tsx b/app/page.tsx
index 4d917f1..e824e6e 100644
--- a/app/page.tsx
+++ b/app/page.tsx
@@ -480,8 +480,11 @@ export default function Home() {
 
   const visibleFiles = useMemo(() => {
     const cleanQuery = query.trim().toLowerCase();
-    if (!cleanQuery) return files;
-    return files.filter((file) => file.path.toLowerCase().includes(cleanQuery));
+    return files.flatMap((file, index) =>
+      !cleanQuery || file.path.toLowerCase().includes(cleanQuery)
+        ? [{ file, index }]
+        : [],
+    );
   }, [files, query]);
 
   if (!snapshot) {
@@ -918,8 +921,7 @@ export default function Home() {
               className="picker-list"
               id="file-picker-list"
             >
-              {visibleFiles.map((file) => {
-                const index = files.findIndex((item) => item.path === file.path);
+              {visibleFiles.map(({ file, index }) => {
                 const active = file.path === currentFile.path;
                 return (
                   <button
diff --git a/docs/content/agent-notes.mdx b/docs/content/agent-notes.mdx
index 17c7e28..59a08ee 100644
--- a/docs/content/agent-notes.mdx
+++ b/docs/content/agent-notes.mdx
@@ -6,8 +6,11 @@ sidebar:
 ---
 
 A coding agent writes short notes for each changed file by default. Diffsplain
-tries Codex, Claude, Copilot, Cursor, then OpenCode, and uses the first installed
-CLI. Each CLI uses its current login.
+tries Codex, Claude, Copilot, then OpenCode, and uses the first installed CLI.
+Each CLI uses its current login. Cursor detection does not mean support:
+Diffsplain detects it only to give a clear unsupported-provider result. Cursor
+stays disabled for note generation because it has no supported read-only,
+no-network, no-tool mode.
 
 Use a plain diff when you do not want notes:
 
diff --git a/docs/content/development.mdx b/docs/content/development.mdx
index a4c3f8b..1b82cd7 100644
--- a/docs/content/development.mdx
+++ b/docs/content/development.mdx
@@ -165,9 +165,12 @@ corepack pnpm run cloud:check
 
 `cloud:check` runs the clean-checkout gate and the provider/browser tests.
 Those tests use fake coding providers and a fake browser command. Real Codex,
-Claude, Copilot, Cursor, OpenCode, GitHub, or browser login is optional and is
-needed only for a live integration task. Keep credentials in Codex environment
-settings, not checked-in rules or scripts.
+Claude, Copilot, OpenCode, GitHub, or browser login is optional and is needed
+only for a live integration task. Diffsplain tries Codex, Claude, Copilot, then
+OpenCode for notes. Cursor detection does not mean support: it is detected only
+to report that Cursor is unsupported. Cursor stays disabled because it has no
+supported read-only, no-network, no-tool mode. Keep credentials in Codex
+environment settings, not checked-in rules or scripts.
 
 To test the linked-worktree path itself, run:
 
diff --git a/docs/content/index.mdx b/docs/content/index.mdx
index 70bf878..404e433 100644
--- a/docs/content/index.mdx
+++ b/docs/content/index.mdx
@@ -11,8 +11,11 @@ patch on the left and a short coding agent note on the right.
 
 ## Start a review
 
-You need Node.js 22.13 or newer and a signed-in Codex, Claude, Copilot, Cursor,
-or OpenCode CLI.
+You need Node.js 22.13 or newer and a signed-in Codex, Claude, Copilot, or
+OpenCode CLI. Diffsplain tries Codex, Claude, Copilot, then OpenCode when you
+do not choose one. Cursor detection does not mean support: it is detected only
+to report that Cursor is unsupported. Cursor has no supported read-only,
+no-network, no-tool mode required for note generation, so it stays disabled.
 
 ```sh
 npx diffsplain
diff --git a/package.json b/package.json
index 5d0134c..a8bfcad 100644
--- a/package.json
+++ b/package.json
@@ -76,7 +76,7 @@
     "test": "pnpm run test:unit && pnpm run test:integration && pnpm run test:coverage && pnpm run test:browser && pnpm run test:platform",
     "test:unit": "node --test tests/access-token.test.mjs tests/automation-trust.test.mjs tests/cache.test.mjs tests/cli-args.test.mjs tests/cli-docs.test.mjs tests/coding-agents.test.mjs tests/data-contract.test.mjs tests/doctor.test.mjs tests/landing-demo.test.mjs tests/package-manifest.test.mjs tests/plan-ledger.test.mjs tests/presenter-runtime.test.mjs tests/product-gate.test.mjs tests/release.test.mjs tests/summary-path.test.mjs tests/support-record.test.mjs tests/test-lanes.test.mjs tests/tool-profiles.test.mjs",
     "test:integration": "pnpm run build && node --test --test-concurrency=1 tests/dev.test.mjs tests/generate-summaries.test.mjs tests/live-update-speed.test.mjs tests/performance-gate.test.mjs tests/present-agent.test.mjs tests/present-help.test.mjs tests/present-instances.test.mjs tests/presenter-recovery.test.mjs tests/remote-targets.test.mjs tests/rendered-html.test.mjs tests/serve-built.test.mjs tests/setup-environments.test.mjs",
-    "test:coverage": "pnpm run build && c8 node --test --test-concurrency=1 tests/cli-args.test.mjs tests/generate-summaries.test.mjs tests/present-agent.test.mjs tests/present-help.test.mjs tests/present-instances.test.mjs tests/remote-targets.test.mjs",
+    "test:coverage": "pnpm run build && c8 node --test --test-concurrency=1 tests/cli-args.test.mjs tests/generate-summaries.test.mjs tests/present-agent.test.mjs tests/present-help.test.mjs tests/present-instances.test.mjs tests/remote-targets.test.mjs tests/serve-built.test.mjs",
     "test:browser": "pnpm run build && node --test tests/browser/*.test.mjs",
     "test:browser:install": "playwright install chromium",
     "test:cloud": "node --test tests/generate-summaries.test.mjs tests/present-agent.test.mjs",
diff --git a/scripts/build-diff-data.mjs b/scripts/build-diff-data.mjs
index a70c4e1..481329b 100644
--- a/scripts/build-diff-data.mjs
+++ b/scripts/build-diff-data.mjs
@@ -4,13 +4,15 @@ import { execFileSync, spawnSync } from 'node:child_process';
 import { createHash } from 'node:crypto';
 import {
   existsSync,
+  lstatSync,
   mkdirSync,
   readFileSync,
+  readlinkSync,
   renameSync,
   statSync,
   writeFileSync,
 } from 'node:fs';
-import { dirname, relative, resolve } from 'node:path';
+import { basename, dirname, relative, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { summaryPath } from './summary-path.mjs';
 
@@ -1088,7 +1090,7 @@ function build() {
   const change = changeSummary(sourceSummaries.change, target.changeDefaults);
   const content = {
     repo: {
-      name: remoteRepository?.name || repo.split('/').pop(),
+      name: remoteRepository?.name || basename(repo),
       root: localWorkspace ? repo : target.remote?.url || repo,
       base: target.base,
       head: target.head,
@@ -1146,6 +1148,29 @@ function build() {
   return true;
 }
 
+function untrackedFileKind(stat) {
+  if (stat.isFile()) return 'file';
+  if (stat.isSymbolicLink()) return 'symlink';
+  if (stat.isDirectory()) return 'directory';
+  return 'other';
+}
+
+function fingerprintUntrackedPath(content, path) {
+  const stat = lstatSync(resolve(repo, path), { bigint: true });
+  content.update(path);
+  content.update('\0');
+  content.update(untrackedFileKind(stat));
+  content.update('\0');
+  content.update(String(stat.size));
+  content.update('\0');
+  content.update(String(stat.mtimeNs));
+  content.update('\0');
+  if (stat.isSymbolicLink()) {
+    content.update(readlinkSync(resolve(repo, path)));
+    content.update('\0');
+  }
+}
+
 function fingerprint() {
   let summariesTime = '';
   if (!ignoreSummaryWatch && !noSummaries) {
@@ -1163,7 +1188,7 @@ function fingerprint() {
   }
   const content = createHash('sha256');
   content.update(
-    tryRepo(['diff', '--no-ext-diff', '--binary', 'HEAD', '--']),
+    tryRepo(['diff', '--no-ext-diff', '--no-textconv', '--binary', 'HEAD', '--']),
   );
   const untracked = tryRepo([
     'ls-files',
@@ -1175,10 +1200,7 @@ function fingerprint() {
     .filter((path) => path && !excludedPaths.has(path))
     .sort();
   for (const path of untracked) {
-    content.update('\0');
-    content.update(path);
-    content.update('\0');
-    content.update(readFileSync(resolve(repo, path)));
+    fingerprintUntrackedPath(content, path);
   }
   return [
     tryRepo(['rev-parse', 'HEAD']),
@@ -1202,18 +1224,38 @@ const refresh = () => {
 
 const started = refresh();
 if (watching && started) {
-  let last = fingerprint();
+  let last;
   let remoteWait = 0;
-  const watcher = setInterval(() => {
-    const next = fingerprint();
-    remoteWait += watchInterval;
-    const remoteDue = remoteMode && remoteWait >= remoteRefreshInterval;
-    if (next !== last || remoteDue || watchContent) {
-      last = next;
-      remoteWait = 0;
-      if (!refresh()) clearInterval(watcher);
+  let watcher;
+  const stopWatching = (error) => {
+    console.error(error instanceof Error ? error.message : String(error));
+    process.exitCode = 1;
+    if (watcher) clearInterval(watcher);
+  };
+  const poll = () => {
+    try {
+      const next = fingerprint();
+      if (last === undefined) {
+        last = next;
+        return true;
+      }
+      remoteWait += watchInterval;
+      const remoteDue = remoteMode && remoteWait >= remoteRefreshInterval;
+      if (next !== last || remoteDue || watchContent) {
+        last = next;
+        remoteWait = 0;
+        if (!refresh()) {
+          clearInterval(watcher);
+          return false;
+        }
+      }
+      return true;
+    } catch (error) {
+      stopWatching(error);
+      return false;
     }
-  }, watchInterval);
+  };
+  if (poll()) watcher = setInterval(poll, watchInterval);
 } else if (watching) {
   process.exitCode = 1;
 }
diff --git a/scripts/cache.mjs b/scripts/cache.mjs
index f9c69c3..d2d631a 100644
--- a/scripts/cache.mjs
+++ b/scripts/cache.mjs
@@ -40,32 +40,14 @@ function leaseRecord(path) {
   }
 }
 
-function leaseOwnerIsActive(record) {
-  return (
-    record?.hostname === hostname() &&
-    Number.isSafeInteger(record.pid) &&
-    processIsAlive(record.pid)
-  );
-}
-
 function leaseIsActive(path, now = Date.now(), duration = leaseDurationMs) {
   try {
-    if (leaseOwnerIsActive(leaseRecord(path))) return true;
     return now - statSync(path).mtimeMs < duration;
   } catch {
     return false;
   }
 }
 
-function processIsAlive(pid) {
-  try {
-    process.kill(pid, 0);
-    return true;
-  } catch (error) {
-    return error?.code === 'EPERM';
-  }
-}
-
 function createLease(path, record, duration) {
   const descriptor = openSync(path, 'wx', 0o600);
   writeFileSync(descriptor, `${JSON.stringify(record)}\n`);
@@ -116,7 +98,6 @@ function rejectActiveLease(active, path) {
 function handleLeaseConflict(error, path, now, duration) {
   rejectNonConflict(error);
   const observed = leaseRecord(path);
-  rejectActiveLease(leaseOwnerIsActive(observed), path);
   rejectActiveLease(leaseIsActive(path, now, duration), path);
   removeStaleLease(path, observed?.token);
 }
diff --git a/tests/browser/review-journey.test.mjs b/tests/browser/review-journey.test.mjs
index 17ea3e1..01dcb71 100644
--- a/tests/browser/review-journey.test.mjs
+++ b/tests/browser/review-journey.test.mjs
@@ -120,6 +120,21 @@ function longFileListFixture() {
   );
 }
 
+function filteredFileListFixture() {
+  return snapshot(
+    "filtered-file-list",
+    Array.from({ length: 60 }, (_, index) => {
+      const number = String(index + 1).padStart(2, "0");
+      return textFile(
+        index % 2 === 1
+          ? `src/match-file-${String((index + 1) / 2).padStart(2, "0")}.ts`
+          : `src/other-file-${number}.ts`,
+        `Explain file ${number}`,
+      );
+    }),
+  );
+}
+
 async function writeSnapshot(value) {
   await writeFile(output, `${JSON.stringify(value, null, 2)}\n`);
 }
@@ -880,3 +895,57 @@ test("centers the selected file when reopening the picker", async () => {
     },
   );
 });
+
+test("keeps filtered picker indexes and full-snapshot keyboard navigation aligned", async () => {
+  await runReviewJourney(
+    "filtered picker indexes",
+    { viewport: { width: 1280, height: 800 } },
+    async (page) => {
+      await writeSnapshot(filteredFileListFixture());
+      await page.goto(serverUrl);
+      await page.getByRole("heading", { name: "Explain file 01" }).waitFor();
+
+      const controls = pickerControls(page);
+      await controls.trigger.click();
+      await controls.search.fill("match-file");
+      const selectedRow = page.getByRole("button", {
+        name: /src\/match-file-30\.ts/i,
+      });
+      assert.equal(
+        await page.locator(".picker-row").first().locator(".picker-index").textContent(),
+        "02",
+      );
+      assert.equal(await selectedRow.locator(".picker-index").textContent(), "60");
+      await selectedRow.click();
+      await page.getByRole("heading", { name: "Explain file 60" }).waitFor();
+      assert.match(
+        await controls.trigger.getAttribute("aria-label"),
+        /Current file 60 of 60: src\/match-file-30\.ts/,
+      );
+
+      await controls.trigger.click();
+      await controls.dialog.waitFor();
+      await page.waitForFunction(() => {
+        const list = document.querySelector(".picker-list");
+        const active = document.querySelector(".picker-row--active");
+        if (!list || !active) return false;
+        const listBounds = list.getBoundingClientRect();
+        const activeBounds = active.getBoundingClientRect();
+        const listCenter = listBounds.top + listBounds.height / 2;
+        const activeCenter = activeBounds.top + activeBounds.height / 2;
+        return Math.abs(listCenter - activeCenter) <= 1;
+      });
+      assert.match(
+        await page.locator(".picker-row--active").textContent(),
+        /src\/match-file-30\.ts/,
+      );
+
+      await controls.close.click();
+      await controls.dialog.waitFor({ state: "hidden" });
+      await controls.trigger.press("ArrowLeft");
+      await page.getByRole("heading", { name: "Explain file 59" }).waitFor();
+      await controls.trigger.press("ArrowRight");
+      await page.getByRole("heading", { name: "Explain file 60" }).waitFor();
+    },
+  );
+});
diff --git a/tests/cache.test.mjs b/tests/cache.test.mjs
index 493d167..c0c4811 100644
--- a/tests/cache.test.mjs
+++ b/tests/cache.test.mjs
@@ -32,7 +32,7 @@ test('fences a delayed writer after stale-lease recovery', async () => {
     const older = acquireLease(lock, {
       token: 'older',
       now,
-      pid: 999_999,
+      pid: process.pid,
     });
     publishLeaseFile(older, note, 'older result');
     await utimes(lock, new Date(now - leaseDurationMs - 1), new Date(now - leaseDurationMs - 1));
@@ -49,6 +49,28 @@ test('fences a delayed writer after stale-lease recovery', async () => {
   }
 });
 
+test('keeps a fresh lease active when its recorded PID is dead', async () => {
+  const root = await mkdtemp(join(tmpdir(), 'diffsplain-cache-'));
+  const lock = join(root, 'summaries', 'target.json.lock');
+  const now = Date.now();
+  let lease;
+  try {
+    lease = acquireLease(lock, {
+      token: 'fresh-dead-pid',
+      now,
+      pid: 999_999,
+    });
+
+    assert.throws(
+      () => acquireLease(lock, { token: 'newer', now }),
+      /already being generated/i,
+    );
+  } finally {
+    if (lease) releaseLease(lease);
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
 test('does not remove a new lease found during stale recovery', async () => {
   const root = await mkdtemp(join(tmpdir(), 'diffsplain-cache-'));
   const lock = join(root, 'summaries', 'target.json.lock');
diff --git a/tests/cli-docs.test.mjs b/tests/cli-docs.test.mjs
index 9a0950a..e682b2f 100644
--- a/tests/cli-docs.test.mjs
+++ b/tests/cli-docs.test.mjs
@@ -6,11 +6,18 @@ import {
   helpText,
   parseCliArgs,
 } from '../scripts/cli-args.mjs';
+import {
+  agentDisabledReason,
+  enabledCodingAgents,
+} from '../scripts/coding-agents.mjs';
 
-const [docs, agentNotes, packageText] = await Promise.all([
+const [docs, agentNotes, development, index, packageText, product] = await Promise.all([
   readFile(new URL('../docs/content/cli.mdx', import.meta.url), 'utf8'),
   readFile(new URL('../docs/content/agent-notes.mdx', import.meta.url), 'utf8'),
+  readFile(new URL('../docs/content/development.mdx', import.meta.url), 'utf8'),
+  readFile(new URL('../docs/content/index.mdx', import.meta.url), 'utf8'),
   readFile(new URL('../package.json', import.meta.url), 'utf8'),
+  readFile(new URL('../PRODUCT.md', import.meta.url), 'utf8'),
 ]);
 
 test('lists each accepted option in public help and the CLI reference', () => {
@@ -44,6 +51,32 @@ test('documents provider inputs and limits', () => {
   assert.doesNotMatch(agentNotes, /--agent claude[\s\S]{0,100}--reasoning/);
 });
 
+test('documents the enabled provider order and Cursor boundary', () => {
+  const providerNames = enabledCodingAgents.map(
+    (agent) => (agent === 'opencode'
+      ? 'OpenCode'
+      : agent[0].toUpperCase() + agent.slice(1)),
+  );
+  const providerOrder =
+    `${providerNames.slice(0, -1).join(', ')}, then ${providerNames.at(-1)}`;
+  const cursorBoundary = agentDisabledReason('cursor')
+    ?.match(/read-only, no-network, no-tool mode/)?.[0];
+  assert.ok(cursorBoundary);
+
+  for (const document of [product, index, agentNotes, development]) {
+    const text = document.replace(/\s+/g, ' ');
+    assert.match(text, new RegExp(providerOrder));
+    assert.match(text, /Cursor detection does not mean support/i);
+    assert.match(text, /Cursor.{0,100}unsupported/i);
+    assert.match(text, new RegExp(cursorBoundary));
+  }
+
+  assert.doesNotMatch(
+    development.replace(/\s+/g, ' '),
+    /Cursor.{0,100}(?:sign in|login)/i,
+  );
+});
+
 test('derives documented numeric defaults and bounds from the parser', () => {
   const batchSize = cliOptions['--batch-size'];
   const jobs = cliOptions['--jobs'];
diff --git a/tests/platform-shell.test.mjs b/tests/platform-shell.test.mjs
index 7a5a335..b83bed8 100644
--- a/tests/platform-shell.test.mjs
+++ b/tests/platform-shell.test.mjs
@@ -1,12 +1,18 @@
 import assert from 'node:assert/strict';
-import { chmod, link, mkdtemp, rm, writeFile } from 'node:fs/promises';
+import { execFileSync } from 'node:child_process';
+import { chmod, link, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
 import { basename, join } from 'node:path';
 import test from 'node:test';
+import { fileURLToPath } from 'node:url';
 import { findCommand } from '../scripts/coding-agents.mjs';
 import { doctorReport } from '../scripts/doctor.mjs';
 import { npmCommand } from '../scripts/release.mjs';
 
+const builder = fileURLToPath(
+  new URL('../scripts/build-diff-data.mjs', import.meta.url),
+);
+
 async function fakeCommand(directory, name) {
   if (process.platform === 'win32') {
     const path = join(directory, `${name}.EXE`);
@@ -65,3 +71,45 @@ test('uses the host npm launcher without a shell wrapper', () => {
   assert.equal(npmCommand('darwin'), 'npm');
   assert.equal(npmCommand('win32'), 'npm.cmd');
 });
+
+test('uses the checkout basename in builder output', async () => {
+  const root = await mkdtemp(join(tmpdir(), 'diffsplain-platform-builder-'));
+  const repo = join(root, 'platform-repo');
+  const output = join(root, 'diff-data.json');
+
+  try {
+    execFileSync('git', ['init', '-q', '-b', 'main', repo]);
+    for (const [key, value] of [
+      ['user.email', 'diffsplain@example.test'],
+      ['user.name', 'Diffsplain'],
+      ['commit.gpgsign', 'false'],
+    ]) {
+      execFileSync('git', ['-C', repo, 'config', key, value]);
+    }
+    await writeFile(join(repo, 'file.txt'), 'before\n');
+    execFileSync('git', ['-C', repo, 'add', 'file.txt']);
+    execFileSync('git', ['-C', repo, 'commit', '-qm', 'base']);
+    await writeFile(join(repo, 'file.txt'), 'after\n');
+
+    execFileSync(
+      process.execPath,
+      [
+        builder,
+        '--worktree',
+        '--repo',
+        repo,
+        '--no-summaries',
+        '--output',
+        output,
+      ],
+      { stdio: 'pipe' },
+    );
+
+    const payload = JSON.parse(await readFile(output, 'utf8'));
+    assert.equal(payload.repo.name, basename(repo));
+    assert.notEqual(payload.repo.name, repo);
+    assert.equal(payload.repo.root, repo);
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
diff --git a/tests/remote-targets.test.mjs b/tests/remote-targets.test.mjs
index 5eedd31..a93faff 100644
--- a/tests/remote-targets.test.mjs
+++ b/tests/remote-targets.test.mjs
@@ -1,12 +1,21 @@
 import assert from "node:assert/strict";
 import { execFileSync, spawn, spawnSync } from "node:child_process";
 import { existsSync, readFileSync } from "node:fs";
-import { chmod, mkdir, mkdtemp, readFile, rm, writeFile } from "node:fs/promises";
+import {
+  chmod,
+  mkdir,
+  mkdtemp,
+  readFile,
+  rm,
+  symlink,
+  writeFile,
+} from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import test from "node:test";
 
 const script = new URL("../scripts/build-diff-data.mjs", import.meta.url).pathname;
+const unavailableSymlinkCodes = new Set(["EACCES", "EPERM"]);
 
 function git(repo, ...args) {
   return execFileSync("git", ["-C", repo, ...args], {
@@ -163,13 +172,14 @@ async function publishFeatureUpdate(fixture, path, content) {
   return head;
 }
 
-function startWatcher(repo, args) {
+function startWatcher(repo, args, options = {}) {
   const child = spawn(
     process.execPath,
     [script, "--repo", repo, ...args],
     {
       env: {
         ...process.env,
+        ...options.env,
         DIFFSPLAIN_WATCH_INTERVAL_MS: "25",
         DIFFSPLAIN_REMOTE_REFRESH_INTERVAL_MS: "100",
       },
@@ -197,6 +207,16 @@ async function stopIfRunning(watched) {
   if (watched?.child.exitCode === null) await stop(watched.child);
 }
 
+async function createDirectorySymlink(target, link) {
+  try {
+    await symlink(target, link, "dir");
+    return undefined;
+  } catch (error) {
+    if (unavailableSymlinkCodes.has(error.code)) return error.code;
+    throw error;
+  }
+}
+
 test("builds a remote branch range without changing the checkout", async () => {
   const fixture = await makeRemoteRepo();
   const output = join(fixture.root, "branch.json");
@@ -633,9 +653,12 @@ test("stops remote and pull-request lookups without replacing complete data", as
 test("watches local changes without changing the selected target", async () => {
   const fixture = await makeRemoteRepo();
   const localOutput = join(fixture.root, "local-watch.json");
+  const firstContent = "local update\n";
+  const secondContent = "fresh update\n";
   let watched;
 
   try {
+    assert.equal(Buffer.byteLength(firstContent), Buffer.byteLength(secondContent));
     watched = startWatcher(
       fixture.repo,
       [
@@ -651,7 +674,7 @@ test("watches local changes without changing the selected target", async () => {
       (payload) => payload.repo.target.kind === "checkout",
     );
     await new Promise((resolve) => setTimeout(resolve, 150));
-    await writeFile(join(fixture.repo, "watched.txt"), "local update\n");
+    await writeFile(join(fixture.repo, "watched.txt"), firstContent);
     const local = await waitForSnapshot(
       localOutput,
       watched,
@@ -659,14 +682,14 @@ test("watches local changes without changing the selected target", async () => {
     );
     assert.equal(local.repo.target.kind, "checkout");
 
-    await writeFile(join(fixture.repo, "watched.txt"), "local update again\n");
+    await writeFile(join(fixture.repo, "watched.txt"), secondContent);
     const refreshed = await waitForSnapshot(
       localOutput,
       watched,
       (payload) =>
         payload.files
           .find((file) => file.path === "watched.txt")
-          ?.patch.includes("local update again"),
+          ?.patch.includes("fresh update"),
     );
     assert.equal(refreshed.repo.target.kind, "checkout");
   } finally {
@@ -675,6 +698,118 @@ test("watches local changes without changing the selected target", async () => {
   }
 });
 
+test("does not run text converters while watching local changes", async () => {
+  const fixture = await makeRemoteRepo();
+  const localOutput = join(fixture.root, "textconv-watch.json");
+  const marker = join(fixture.root, "textconv-ran");
+  let watched;
+
+  try {
+    await writeFile(join(fixture.repo, ".gitattributes"), "converted.txt diff=marker\n");
+    await writeFile(join(fixture.repo, "converted.txt"), "before\n");
+    git(fixture.repo, "add", ".gitattributes", "converted.txt");
+    git(fixture.repo, "commit", "-qm", "add converted file");
+    git(
+      fixture.repo,
+      "config",
+      "diff.marker.textconv",
+      `sh -c 'touch ${marker}; cat'`,
+    );
+    await writeFile(join(fixture.repo, "converted.txt"), "after\n");
+
+    watched = startWatcher(fixture.repo, ["--checkout", "--watch", "--output", localOutput]);
+    await waitForSnapshot(localOutput, watched, () => true);
+    await new Promise((resolve) => setTimeout(resolve, 150));
+    assert.equal(existsSync(marker), false);
+    assert.equal(watched.child.exitCode, null);
+  } finally {
+    await stopIfRunning(watched);
+    await rm(fixture.root, { recursive: true, force: true });
+  }
+});
+
+test("watches untracked symlinks without reading their targets", async (t) => {
+  const fixture = await makeRemoteRepo();
+  const localOutput = join(fixture.root, "symlink-watch.json");
+  const outside = join(fixture.root, "outside");
+  const link = join(fixture.repo, "outside-link");
+  let watched;
+
+  try {
+    await mkdir(outside);
+    const unavailable = await createDirectorySymlink(outside, link);
+    if (unavailable) {
+      t.skip(`symlink creation is unavailable: ${unavailable}`);
+      return;
+    }
+    watched = startWatcher(fixture.repo, ["--checkout", "--watch", "--output", localOutput]);
+    const snapshot = await waitForSnapshot(
+      localOutput,
+      watched,
+      (payload) => payload.files.some((file) => file.path === "outside-link"),
+    );
+    assert.equal(snapshot.files.find((file) => file.path === "outside-link")?.status, "added");
+    await new Promise((resolve) => setTimeout(resolve, 150));
+    assert.equal(watched.child.exitCode, null);
+  } finally {
+    await stopIfRunning(watched);
+    await rm(fixture.root, { recursive: true, force: true });
+  }
+});
+
+test("exits cleanly when a fingerprint path disappears during polling", async () => {
+  const fixture = await makeRemoteRepo();
+  const localOutput = join(fixture.root, "fingerprint-race-watch.json");
+  const bin = join(fixture.root, "git-proxy");
+  const proxy = join(bin, "git");
+  const marker = join(fixture.root, "delete-on-ls-files");
+  const raced = join(fixture.repo, "raced.txt");
+  let watched;
+
+  try {
+    await writeFile(raced, "race\n");
+    await mkdir(bin);
+    await writeFile(
+      proxy,
+      `#!/usr/bin/env node
+const { existsSync, unlinkSync } = require("node:fs");
+const { spawnSync } = require("node:child_process");
+const args = process.argv.slice(2);
+const result = spawnSync(process.env.DIFFSPLAIN_REAL_GIT, args, { encoding: "utf8" });
+process.stdout.write(result.stdout || "");
+process.stderr.write(result.stderr || "");
+if (args.includes("ls-files") && existsSync(process.env.DIFFSPLAIN_RACE_MARKER)) {
+  unlinkSync(process.env.DIFFSPLAIN_RACE_PATH);
+}
+process.exit(result.status ?? 1);
+`,
+    );
+    await chmod(proxy, 0o755);
+    watched = startWatcher(
+      fixture.repo,
+      ["--checkout", "--watch", "--output", localOutput],
+      {
+        env: {
+          DIFFSPLAIN_RACE_MARKER: marker,
+          DIFFSPLAIN_RACE_PATH: raced,
+          DIFFSPLAIN_REAL_GIT: process.env.PATH.split(":").map((path) => join(path, "git")).find(existsSync),
+          PATH: `${bin}:${process.env.PATH}`,
+        },
+      },
+    );
+    await waitForSnapshot(localOutput, watched, () => true);
+    await writeFile(marker, "delete the next fingerprint path\n");
+    await waitFor(() => watched.child.exitCode !== null);
+    assert.equal(watched.child.exitCode, 1);
+    assert.match(watched.logs(), /ENOENT: no such file or directory, lstat/);
+    assert.equal((watched.logs().match(/ENOENT: no such file or directory, lstat/g) || []).length, 1);
+    assert.doesNotMatch(watched.logs(), /\n\s*at /);
+  } finally {
+    await stopIfRunning(watched);
+    await rm(fixture.root, { recursive: true, force: true });
+  }
+});
+
 test("periodically refreshes remote targets without changing the checkout", async () => {
   const fixture = await makeRemoteRepo();
   const remoteOutput = join(fixture.root, "remote-watch.json");
diff --git a/tests/test-lanes.test.mjs b/tests/test-lanes.test.mjs
index 8f800a3..3e67d73 100644
--- a/tests/test-lanes.test.mjs
+++ b/tests/test-lanes.test.mjs
@@ -12,6 +12,28 @@ function listedTests(command) {
   return command.match(/tests\/[^ ]+\.test\.mjs/g) || [];
 }
 
+function workflowSteps(workflow) {
+  return [...workflow.matchAll(
+    /^(?<indent> *)- name: (?<name>.+)\n(?<body>(?:^\k<indent> {2}.+(?:\n|$))*)/gm,
+  )].map(({ groups }) => groups);
+}
+
+function assertPnpmCacheSetup(workflow, expectedCount) {
+  const steps = workflowSteps(workflow);
+  const nodeSetups = steps
+    .map((step, index) => ({ ...step, index }))
+    .filter(({ body }) => body.includes('uses: actions/setup-node@v6'));
+
+  assert.equal(nodeSetups.length, expectedCount);
+  for (const { body, index } of nodeSetups) {
+    assert.match(body, /^\s+cache: pnpm$/m);
+    assert.match(body, /^\s+cache-dependency-path: pnpm-lock.yaml$/m);
+    assert.ok(index > 0, 'Node setup must follow Corepack');
+    assert.match(steps[index - 1].body, /^\s+run: corepack enable$/m);
+  }
+  assert.doesNotMatch(workflow, /^\s+run: corepack pnpm\b/m);
+}
+
 test('keeps the test lanes separate and composes the complete test gate', async () => {
   const packageJson = await json('package.json');
   const scripts = packageJson.scripts;
@@ -34,6 +56,7 @@ test('keeps the test lanes separate and composes the complete test gate', async
   assert.match(scripts['test:integration'], /--test-concurrency=1/);
   assert.match(scripts['test:coverage'], /pnpm run build/);
   assert.match(scripts['test:coverage'], /--test-concurrency=1/);
+  assert.match(scripts['test:coverage'], /tests\/serve-built\.test\.mjs/);
   assert.equal(
     scripts['test:browser'],
     'pnpm run build && node --test tests/browser/*.test.mjs',
@@ -73,6 +96,7 @@ test('holds each core path to the documented coverage floor', async () => {
     'scripts/build-diff-data.mjs',
     'scripts/generate-summaries.mjs',
     'scripts/present.mjs',
+    'scripts/serve-built.mjs',
   ]);
   assert.deepEqual(
     {
@@ -106,7 +130,24 @@ test('runs pull request lanes on Linux and scheduled shell checks elsewhere', as
   assert.match(workflow, /schedule:/);
   assert.match(workflow, /macos-15/);
   assert.match(workflow, /windows-2025/);
-  assert.match(workflow, /run: corepack pnpm install --frozen-lockfile/g);
+  assert.equal(
+    workflow.match(/run: pnpm install --frozen-lockfile/g)?.length,
+    5,
+  );
   assert.match(workflow, /permissions:\n  contents: read/);
   assert.doesNotMatch(workflow, /pull_request_target:|secrets\.|write-all/);
 });
+
+test('caches pnpm dependencies before each Node setup', async () => {
+  const productGate = await readFile(
+    new URL('../.github/workflows/product-gate.yml', import.meta.url),
+    'utf8',
+  );
+  const testLanes = await readFile(
+    new URL('../.github/workflows/test-lanes.yml', import.meta.url),
+    'utf8',
+  );
+
+  assertPnpmCacheSetup(productGate, 1);
+  assertPnpmCacheSetup(testLanes, 5);
+});