[vitormattos]

Summary

Apply one consistent LibreSign convention for translator hints across the frontend and PHP backend, fix ambiguous translation calls, and prevent repeated or malformed hints in CI.

Depends on #9360. That PR corrects the approval workflow and removes the triplicated hints on the Approved and Pending filters. This follow-up standardizes the rest of the project and protects the convention automatically.

LibreSign convention

• Use // TRANSLATORS Explain the context. in JavaScript, TypeScript and PHP, or <!-- TRANSLATORS Explain the context. --> in Vue templates.
• No colon after the TRANSLATORS marker. This is a LibreSign code-style decision; Nextcloud supports the optional punctuation.
• Use one context hint immediately before each relevant t() or n() call. Never repeat hints consecutively above a single translation.
• Split conditional or nested translation calls into distinct source lines so each message can receive its own context.
• When the same text is translated at different call sites, separate hints are acceptable if each is attached to a different translation call.

Changes

• Normalize 42 remaining translator hints in Vue/TypeScript/PHP code to the project's colonless convention. Six hints and four duplicated comments are corrected in the prerequisite fix(approval): clarify document review and sign-off #9360.
• Preserve the earlier refactor of 13 ambiguous same-line translation sites (document validation, envelopes, policy dialogs, filters, accessible labels).
• Extend scripts/check-translator-hints.mjs and its existing npm run lint CI integration to block:
  • multiple LibreSign translations on one source line;
  • a colon immediately after the TRANSLATORS marker;
  • consecutive translator hints above a single translation.
• Check tracked Vue/JS/TS/PHP sources under src, lib, appinfo, tests, and scripts (excluding the checker's own deliberately malformed test fixtures and generated OpenAPI types).
• Add regression tests for the exact three identical hints reported on the approval filter, malformed colon punctuation, and legitimate independent translation calls.
• Keep CONTRIBUTING.md and AGENTS.md as brief pointers to the canonical developer-manual Translation page, maintained by LibreSign/documentation#124. Remove the duplicated tutorial from the application repository.

Documentation dependency: LibreSign/documentation#124 contains the complete contributor explanation, with rendered screenshots and a warning-free Sphinx build. The automated checker stays in this LibreSign application PR.

Validation

• node --test scripts/tests/check-translator-hints.test.mjs: 8 tests passed.
• node scripts/check-translator-hints.mjs: passed across tracked application sources.
• npm run ts:check: passed.
• php -l for each of the five affected PHP files using the Nextcloud development container: passed.
• npm run lint: passed (pre-existing non-blocking lint warnings only).
• Existing focused Vitest comparison: 247 passed, 23 baseline failures reproduced identically on the unchanged parent; not introduced by the translator-hint changes.

Scope: Comments, contributor guidance, localization call organization and CI safeguards. No generated translation catalog changes, new dependencies or modifications to signing behavior. No squash or merge requested.