fix: simplify updater to @mosaic/mosaic only, add explicit tea repo/login flags (#387)

BREAKING CHANGE: Remove legacy @mosaic/cli fallback from update-checker.
The updater now targets only @mosaic/mosaic — legacy package compatibility
is out of scope per approved breaking change.

- update-checker.ts: remove LEGACY_PKG, INSTALLED_PACKAGE_ORDER, candidate
  iteration, and cache key comparison. Single query for @mosaic/mosaic only.
- update-checker.test.ts: remove legacy fallback and cross-contamination
  tests. Add test asserting no @mosaic/cli queries are made.
- pr-merge.sh: add --repo and --login flags to tea merge command; resolve
  OWNER/REPO before case block.
- issue-close.sh: add --repo and --login flags to tea issue commands;
  resolve OWNER/REPO after detect_platform.
- pr-ci-wait.sh: no changes needed (uses curl, not tea).
- detect-platform.sh: no changes needed (provides get_repo_owner/name).

Ref: #387

docs/scratchpads/387-updater-wrapper-gitea-20260404.md

@@ -0,0 +1,54 @@
+# Scratchpad — issue #387 updater simplification + Gitea wrapper repo context
+
+- Objective: simplify updater behavior to `@mosaic/mosaic` only, and fix Gitea wrapper scripts so merge/CI/issue operations work reliably when tea needs explicit repo/login context.
+- Scope:
+  - `packages/mosaic/src/runtime/update-checker.ts`
+  - `packages/mosaic/__tests__/update-checker.test.ts`
+  - any package metadata/version bumps needed
+  - repo-source git wrappers under `packages/mosaic/framework/tools/git/`
+- Constraints:
+  - Jason approved breaking changes; legacy `@mosaic/cli` support is out of scope.
+  - Keep changes focused and mergeable.
+- Acceptance:
+  - updater only targets `@mosaic/mosaic`
+  - wrapper path works on Gitea in this environment without manual repo guessing
+  - PR merges squash-only after green CI
+
+## Progress
+
+### 2026-04-04
+
+#### Update Checker Simplification (DONE)
+
+- Removed `LEGACY_PKG`, `INSTALLED_PACKAGE_ORDER` constants — only `PKG = '@mosaic/mosaic'` remains
+- `getInstalledVersion()` — removed loop over multiple packages, only checks `@mosaic/mosaic`
+- `getLatestVersion()` — removed `installedPackage` parameter and candidate iteration; single query for `@mosaic/mosaic`
+- `checkForUpdate()` — removed `currentPackage`-based cache key comparison; cache is now package-agnostic
+- `RegistryCache` — removed `currentPackage` and `targetPackage` fields
+- `formatUpdateNotice()` — removed `targetChanged` branch (package migration notice no longer relevant)
+- All legacy fallback/compatibility logic removed
+
+#### Test Updates (DONE)
+
+- Removed legacy `@mosaic/cli` fallback test
+- Removed cache cross-contamination test (was testing legacy→modern package transition)
+- Added `does not query legacy @mosaic/cli package` test — asserts no `@mosaic/cli` npm commands are issued
+- Added `returns empty result when package is not installed` test
+- All 8 tests pass ✅
+
+#### Gitea Wrapper Fixes (DONE)
+
+- `pr-merge.sh`:
+  - Added `OWNER=$(get_repo_owner)` / `REPO=$(get_repo_name)` before case block
+  - tea merge command now includes `--repo $OWNER/$REPO --login ${GITEA_LOGIN:-mosaicstack}`
+- `issue-close.sh`:
+  - Added `OWNER=$(get_repo_owner)` / `REPO=$(get_repo_name)` after detect_platform
+  - Both `tea issue comment` and `tea issue close` now include `--repo "$OWNER/$REPO" --login "${GITEA_LOGIN:-mosaicstack}"`
+- `pr-ci-wait.sh`: No changes needed — uses curl API calls (not tea), already passes owner/repo correctly
+- `detect-platform.sh`: No changes needed — provides the `get_repo_owner`/`get_repo_name` functions used by wrappers
+
+#### Verification
+
+- `vitest run` — 8/8 tests pass
+- `tsc --noEmit` — no errors in update-checker.ts (pre-existing workspace dep errors unrelated)
+- `eslint` — clean, no warnings