test(share): cover alias controllers; address PR #214 review

Add the two blocking test-coverage specs requested in the PR #214 review and
clear the cheap non-blocking items.

Must-fix:
- share-alias-redirect.controller.spec.ts: routing/leak guard for the public
  GET /l/:alias resolver (modeled on share-seo.controller.routing.spec). Pins
  302-to-canonical on a hit; SPA index without a 302 for unknown/dangling/
  unreadable aliases and a null workspace (no name-existence leak); defensive
  percent-decoding treated as unknown; self-hosted findFirst vs subdomain
  findByHostname workspace resolution; 404 when no built client index exists.
- share-alias.controller.spec.ts: authz gates with mocked PageRepo/ShareService/
  ShareAliasService/PageAccessService. Covers cross-workspace/nonexistent page
  -> NotFoundException, validateCanEdit, resolveReadableSharePage null ->
  BadRequestException, isSharingAllowed false -> ForbiddenException, set happy
  path delegation, remove() of a dangling alias (pageId null) skipping
  validateCanEdit but still deleting, and for-page validateCanView.

Cheap review items:
- Remove dead Logger import/field from ShareAliasRedirectController.
- Remove dead PagePermissionRepo import/dependency from ShareAliasController.
- Register the new share-alias UI strings in en-US and ru-RU catalogs.
- Add an [Unreleased]/Added CHANGELOG entry for /l/:alias (#205).
- Drop the tautological boilerplate assertions from the migration spec
  (exports up/down; runtime checks of typed entity literals).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/client/public/locales/en-US/translation.json

@@ -1315,5 +1315,15 @@
   "Protocol": "Protocol",
   "How chat requests are sent and how reasoning is surfaced": "How chat requests are sent and how reasoning is surfaced",
   "OpenAI-compatible (surfaces reasoning)": "OpenAI-compatible (surfaces reasoning)",
-  "OpenAI (official)": "OpenAI (official)"
+  "OpenAI (official)": "OpenAI (official)",
+  "Custom address": "Custom address",
+  "A short, memorable link you can point at any shared page.": "A short, memorable link you can point at any shared page.",
+  "Use 2-60 lowercase letters, digits and hyphens": "Use 2-60 lowercase letters, digits and hyphens",
+  "This address is already in use": "This address is already in use",
+  "Move custom address?": "Move custom address?",
+  "Move here": "Move here",
+  "The address \"{{alias}}\" currently points to \"{{title}}\". Move it to this page?": "The address \"{{alias}}\" currently points to \"{{title}}\". Move it to this page?",
+  "The address \"{{alias}}\" is already in use. Move it to this page?": "The address \"{{alias}}\" is already in use. Move it to this page?",
+  "Failed to set custom address": "Failed to set custom address",
+  "Failed to remove custom address": "Failed to remove custom address"
 }