diff --git a/.github/commit-guidelines.md b/.github/commit-guidelines.md
index 41ba41b86e..3a988ce1b3 100644
--- a/.github/commit-guidelines.md
+++ b/.github/commit-guidelines.md
@@ -15,6 +15,7 @@ These align with the gitlint rules run in CI.
 - Wrap lines at 80 characters.
 - Explain what and why over how; link issues like "Fixes #1234" when applicable.
 - No hard tabs, no trailing whitespace.
+- The `Agent-Logs-Url:` footer generated by agent tooling is ignored by gitlint.
 
 ## Helpful commands (Windows PowerShell)
 
diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 0000000000..5cc5108cd5
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,42 @@
+# FieldWorks Copilot Code Review Instructions
+
+## Purpose
+
+Review FieldWorks pull requests for the project-specific risks most likely to
+cause regressions in this Windows/x64, .NET Framework 4.8, native/managed
+desktop application.
+
+## Highest-priority checks
+
+- Verify changes preserve the native-before-managed build ordering enforced by
+  `build.ps1`, `FieldWorks.proj`, and related targets.
+- Flag changes that introduce global COM registration or registry hacks;
+  FieldWorks uses registration-free COM.
+- Check all native, COM, file-system, installer, and process-boundary inputs for
+  validation, encoding assumptions, buffer lengths, and ownership rules.
+- Verify user-visible UI strings are placed in `.resx` resources and remain
+  compatible with Crowdin localization.
+- For C# code, flag C# 8+ syntax and APIs that are not compatible with .NET
+  Framework 4.8 / C# 7.3.
+- For legacy `.csproj` changes, verify new source files are explicitly included
+  and test sources are explicitly excluded where production and test trees mix.
+- Require meaningful test or validation evidence for bug fixes, regressions,
+  parser changes, interlinear display changes, installer changes, and build
+  workflow changes.
+
+## Review focus from recent history
+
+- Recent churn is concentrated in `Src/Utilities`, parser utilities, Allomorph
+  Generator, Interlinear display, build scripts, and installer workflows.
+- Recent bugs include click-handler crashes, stale UI state, layout/display
+  regressions, media-line rework, localization gaps, installer/build fixes, and
+  dependency-version alignment.
+- When those areas change, review null checks, collection bounds, selection
+  state, refresh/invalidation behavior, layout anchoring, localization, and
+  regression-test coverage before style-only concerns.
+
+## Review style
+
+- Prefer concise, actionable comments that explain the FieldWorks-specific risk.
+- Do not request unrelated refactors.
+- Do not rely on external links; cite the relevant rule or file path directly.
diff --git a/.github/instructions/fieldworks-build-installer-review.instructions.md b/.github/instructions/fieldworks-build-installer-review.instructions.md
new file mode 100644
index 0000000000..9e862e909b
--- /dev/null
+++ b/.github/instructions/fieldworks-build-installer-review.instructions.md
@@ -0,0 +1,45 @@
+---
+applyTo: ".github/workflows/**,Build/**,scripts/**,*.ps1,*.proj,*.targets,*.props,Directory.Packages.props,FLExInstaller/**"
+name: "fieldworks-build-installer-review"
+description: "Copilot code review checks for FieldWorks build, CI, dependency, installer, and PowerShell changes"
+---
+
+# Build, CI, Dependency, and Installer Review Checks
+
+## Purpose
+
+Use these checks for build scripts, CI workflows, dependency versions, MSBuild
+targets, installer inputs, and PowerShell helper changes.
+
+## Build and CI integrity
+
+- Preserve native-before-managed ordering and do not bypass `build.ps1` or
+  `test.ps1` for normal validation.
+- Verify build/test process cleanup remains scoped to the current worktree and
+  does not terminate processes from other worktrees.
+- For workflow changes, verify tests run before installer packaging when that
+  ordering affects release confidence.
+- Flag hardcoded absolute paths, machine-specific assumptions, and hidden
+  dependency downloads that are not represented in repo scripts.
+
+## Dependency alignment
+
+- Version changes in `Directory.Packages.props`, `Build/SilVersions.props`,
+  app configs, binding redirects, and local-library scripts should agree.
+- Dependency updates should explain compatibility with .NET Framework 4.8,
+  native x64 requirements, and existing installer/runtime packaging.
+
+## PowerShell and script safety
+
+- Prefer repo wrapper scripts over ad-hoc command pipelines.
+- Check error handling, exit-code propagation, quoting of paths with spaces, and
+  deterministic evidence output.
+- Avoid name-based process termination; use specific process IDs when stopping a
+  process is required.
+
+## Installer evidence
+
+- WiX and installer changes should include validation evidence for bundle/MSI
+  build, install/upgrade/uninstall behavior, logs, and expected footprint.
+- Preserve both WiX 3 and WiX 6 flows unless the change explicitly scopes one
+  toolset.
diff --git a/.github/instructions/fieldworks-interop-review.instructions.md b/.github/instructions/fieldworks-interop-review.instructions.md
new file mode 100644
index 0000000000..96c26bfac7
--- /dev/null
+++ b/.github/instructions/fieldworks-interop-review.instructions.md
@@ -0,0 +1,39 @@
+---
+applyTo: "Src/Common/ViewsInterfaces/**,Src/views/**,Src/Generic/**,Src/Kernel/**,**/*.{cpp,h,hpp,ixx,def}"
+name: "fieldworks-interop-review"
+description: "Copilot code review checks for native, C++/CLI, COM, and managed/native boundary changes"
+---
+
+# Interop and Native Boundary Review Checks
+
+## Purpose
+
+Use these checks for native code, C++/CLI-adjacent code, COM interfaces,
+ViewsInterfaces, Generic, Kernel, and managed/native boundary changes.
+
+## Boundary safety
+
+- Validate untrusted input before it crosses native, COM, file-system, or process
+  boundaries.
+- Check string encoding conversions, buffer lengths, array counts, pointer
+  ownership, lifetime, and nullability on every changed boundary.
+- Avoid throwing exceptions across managed/native boundaries; translate failures
+  into the existing error-reporting pattern.
+- Verify SAL annotations, checked APIs, RAII, and deterministic cleanup are used
+  where applicable.
+
+## COM and ABI stability
+
+- Flag COM GUID, interface layout, vtable order, manifest, or registration-free
+  COM changes for explicit compatibility review.
+- Do not introduce global COM registration, registry hacks, or assumptions that
+  require elevated machine-wide state.
+- Managed wrapper changes should stay consistent with the native contract and
+  include tests or validation that exercise the boundary.
+
+## Build and diagnostics
+
+- Native changes must not hide compiler or MSBuild warnings; fix warnings rather
+  than suppressing them casually.
+- Boundary failures should produce actionable diagnostics without leaking
+  sensitive data or overwhelming normal logs.
diff --git a/.github/instructions/fieldworks-parser-utilities-review.instructions.md b/.github/instructions/fieldworks-parser-utilities-review.instructions.md
new file mode 100644
index 0000000000..29099cd4f6
--- /dev/null
+++ b/.github/instructions/fieldworks-parser-utilities-review.instructions.md
@@ -0,0 +1,40 @@
+---
+applyTo: "Src/Utilities/pcpatrflex/**,Src/Utilities/AlloVarGen/**,Src/LexText/ParserCore/**,Src/LexText/Morphology/**,Src/LexText/Interlinear/**"
+name: "fieldworks-parser-utilities-review"
+description: "Copilot code review checks for parser, morphology, interlinear, PCPATR, and Allomorph Generator changes"
+---
+
+# Parser and Linguistic Utilities Review Checks
+
+## Purpose
+
+Use these checks for parser utilities, morphology, interlinear analysis, PCPATR,
+TonePars, Allomorph Generator, and related test data.
+
+## Correctness and regression coverage
+
+- Parser, morphology, grammar, or transform changes should include acceptance
+  examples or regression tests that show the intended linguistic behavior.
+- For media-line, interlinear display, stale filtering, and preview-pane changes,
+  verify the changed model state triggers display refresh and persistence updates.
+- When large `.fwdata`, grammar, XML, or expected-output files change, verify the
+  diff is intentional and tied to a specific parser or fixture behavior.
+- Flag changes that alter matching, regex, grammar, or word-analysis behavior
+  without edge-case tests for empty values, multiple writing systems, and
+  ambiguous analyses.
+
+## Allomorph and variant generator safety
+
+- Dialog and chooser changes must handle empty collections, deleted items,
+  missing writing systems, and null cast results.
+- Selection state should be restored by stable identifiers or names when object
+  instances can be recreated.
+- New UI text or documentation for these utilities should use resources and
+  remain localizable.
+
+## Test data discipline
+
+- Keep fixture updates scoped: do not refresh broad expected-output files unless
+  the changed behavior requires it.
+- Review paired before/after fixture files together and verify they remain
+  consistent.
diff --git a/.github/instructions/fieldworks-ui-review.instructions.md b/.github/instructions/fieldworks-ui-review.instructions.md
new file mode 100644
index 0000000000..71a5dfedc7
--- /dev/null
+++ b/.github/instructions/fieldworks-ui-review.instructions.md
@@ -0,0 +1,45 @@
+---
+applyTo: "Src/**/*.{cs,resx}"
+name: "fieldworks-ui-review"
+description: "Copilot code review checks for FieldWorks WinForms, xWorks, interlinear display, and localization changes"
+---
+
+# FieldWorks UI Review Checks
+
+## Purpose
+
+Use these checks for managed UI, WinForms dialogs, xWorks, interlinear display,
+and resource changes.
+
+## Crash prevention
+
+- In event handlers and dialog callbacks, verify `sender`, selected items,
+  selected indices, model objects, and cast results are checked before use.
+- Flag `Items[index]`, `SelectedItems[0]`, `SelectedIndex`, or `as Type` casts
+  when bounds or null checks are missing.
+- Verify deleted or replaced model objects cannot remain in chooser lists,
+  cached selections, mediator state, or reference collections.
+- Check that UI updates from background work marshal back to the UI thread.
+
+## Display and layout regressions
+
+- For interlinear, preview pane, dictionary, media-line, and tree/list display
+  changes, verify refresh/invalidation and persistence behavior are covered.
+- Review `TableLayoutPanel`, `FlowLayoutPanel`, anchoring, docking, minimum size,
+  tab order, and resizable dialog behavior when layout files change.
+- Flag display logic changes without corresponding tests or explicit manual
+  validation notes for the affected user workflow.
+
+## Localization and resources
+
+- User-visible strings belong in `.resx` resources, not hardcoded in C#.
+- Resource keys should be stable, descriptive, and reused consistently between
+  code, designer files, and localized resources.
+- When `.resx` files change, verify designer/resource accessors stay in sync.
+
+## Designer safety
+
+- Keep generated initialization in designer files and application logic in the
+  non-designer partial class.
+- Flag manual designer edits that remove disposal, component initialization, or
+  resource manager usage.
diff --git a/.gitlint b/.gitlint
new file mode 100644
index 0000000000..228fc2a76b
--- /dev/null
+++ b/.gitlint
@@ -0,0 +1,6 @@
+[general]
+regex-style-search=true
+
+[ignore-by-body]
+regex=^Agent-Logs-Url:
+ignore=B1
diff --git a/Build/Agent/check-whitespace.ps1 b/Build/Agent/check-whitespace.ps1
index dcfd38ea5d..1e7f2b2c14 100644
--- a/Build/Agent/check-whitespace.ps1
+++ b/Build/Agent/check-whitespace.ps1
@@ -83,7 +83,7 @@ Get-Content check-results.log | ForEach-Object {
 }
 
 if ($problems.Count -gt 0) {
-	Write-Host "`u26A0`uFE0F Please review the output for further information."
+	Write-Host '[WARN] Please review the output for further information.'
 	Write-Host '### A whitespace issue was found in one or more of the commits.'
 	Write-Host 'This check validates commit history from origin/main..HEAD, not just the current working tree.'
 	Write-Host 'If the report names an older commit, fix the file and then amend, squash, or rebase so that commit no longer appears in the branch history.'
diff --git a/Build/Agent/fix-whitespace.ps1 b/Build/Agent/fix-whitespace.ps1
index 324a254a2f..1933489889 100644
--- a/Build/Agent/fix-whitespace.ps1
+++ b/Build/Agent/fix-whitespace.ps1
@@ -78,7 +78,7 @@ if (Test-Path -LiteralPath 'check-results.log') {
 if (-not $fixFiles -or $fixFiles.Count -eq 0) {
 	$base = Get-BaseRef
 	Write-Host "Fixing whitespace for files changed since $base..HEAD"
-	$fixFiles = git diff --name-only "$base"..HEAD
+	$fixFiles = git diff --name-only "$base..HEAD"
 }
 
 $files = $fixFiles | Where-Object { $_ -and (Test-Path $_) }