Frontend: one public entry point (public-api) with an exports map for extensions #886

Goal

The frontend has one public entry point for extensions and embedding apps: src/public-api.ts, reachable by package name (smart-ssh/public-api) through an exports map. Everything an extension may use is exported there; internal module paths are no longer part of the contract, so renaming an internal file does not break anyone outside this repository.

Context

• apps/smart-ssh-community/frontend/package.json (name smart-ssh) has no exports map. Code outside the frontend that builds on it can only import internal files by relative path (…/frontend/src/api, …/src/components/ui, …).
• Items such code needs today, by module:
  • extensions (registry functions, useEntitlements, publishFeatureLocked, FeatureLockedDialog, ModalBackdrop, types) – src/extensions/index.ts
  • extensions/entitlements (Entitlements, Feature, Tier, FeatureLockedPayload)
  • api (commandErrorMessage, commandErrorCode, commandErrorFeatureLocked, listServers, getStartupState) – the central invoke wrapper api.ts:95-106 (reports feature_locked to the dialog bus) is not exported, so callers use the raw invoke and lose the locked-feature dialog
  • components/ui (Button, Field, FIELD_CONTROL_CLASS, …), ErrorBoundary (Frontend: isolate every extension contribution and the app root with an error boundary #880)
  • technicalInputProps (TECHNICAL_INPUT_PROPS), hooks/useIsNarrow, resolveSectionLabel, fileDialog (pickAndReadTextFile), languages (SUPPORTED_LANGUAGES), i18n (settingsStore, initI18n), types (DTO types such as AiProviderConfigDto, ChatSessionSummaryDto, StartupStateDto)
  • bootstrap (Frontend: move the start sequence into an exported bootstrap() for embedding apps #882)
  • in tests: test/matchMedia (installMatchMediaMock, setWide)
• The reactive registry functions come from Extension registry: make document actions and first-run notice extensions reactive #884.

Requirements

• New src/public-api.ts: a header doc comment (English) saying this is the only supported import surface for extensions and embedding apps, with the stability rule (exports change only with a changelog entry and a spec update). It re-exports:
  • everything exported by src/extensions/index.ts
  • entitlement types from extensions/entitlements
  • bootstrap and BootstrapOptions
  • ErrorBoundary and the components/ui building blocks exported by components/ui/index.ts
  • invokeCommand<T>(cmd, args?) – the central wrapper from api.ts:95-106, exported under this name (same behaviour: reports feature_locked to the dialog bus, rethrows unchanged)
  • commandErrorMessage, commandErrorCode, commandErrorFeatureLocked, commandErrorConnectLog, listServers, getStartupState
  • TECHNICAL_INPUT_PROPS, useIsNarrow, resolveSectionLabel, pickAndReadTextFile, SUPPORTED_LANGUAGES, settingsStore, initI18n
  • the DTO types listed under Context (type-only exports)
• New src/test-support.ts re-exporting the test helpers installMatchMediaMock, setWide (and nothing used by production code).
• package.json gets an exports map with exactly "./public-api": "./src/public-api.ts" and "./test-support": "./src/test-support.ts"; the app's own build, dev server, vitest and Playwright keep working (they do not import by package name).
• A vitest guard src/publicApi.test.ts asserts that every name in an explicit list (the list above) is exported by public-api with the expected kind (function/component/object), so removing or renaming an export fails the test.
• Spec 0038 section 4 lists smart-ssh/public-api as the supported surface and states that relative imports of internal files are not supported.

Acceptance Criteria

• src/public-api.ts and src/test-support.ts exist with the exports above.
• invokeCommand behaves like the internal wrapper: test that a rejected call with feature_locked publishes on the feature-locked bus and rethrows the same error object; a rejection without it publishes nothing.
• package.json exports contains exactly the two entries; npm run build, npm test, npm run test:e2e pass.
• A small fixture in the test (import … from "smart-ssh/public-api" resolved through the workspace, or import.meta.resolve) proves the package-name import resolves.
• src/publicApi.test.ts fails when one listed export is removed (counter-check documented in the test).
• Spec 0038 section 4 updated.
• Relevant automated tests pass (npm run lint, npm test, tsc -b).

Technical Notes

• Files: src/public-api.ts, src/test-support.ts, src/publicApi.test.ts (new), src/api.ts (export the wrapper under invokeCommand, keep the internal name working), package.json, docs/specs/0038-repository-app-shell-ci.md.
• Re-export only; do not move code. Keep extensions/index.ts as it is (public-api builds on it).
• scripts/check-tauri-commands.mjs scans invoke("…") call sites; make sure exporting the wrapper does not change what it detects (run npm run check-commands).

Spec impact: update 0038

Open questions

• none

Related Work

• Frontend: isolate every extension contribution and the app root with an error boundary #880, Frontend: move the start sequence into an exported bootstrap() for embedding apps #882, Extension registry: make document actions and first-run notice extensions reactive #884 (block this issue)