fix: rename all packages from @mosaic/* to @mosaicstack/*

- Updated all package.json name fields and dependency references
- Updated all TypeScript/JavaScript imports
- Updated .woodpecker/publish.yml filters and registry paths
- Updated tools/install.sh scope default
- Updated .npmrc registry paths (worktree + host)
- Enhanced update-checker.ts with checkForAllUpdates() multi-package support
- Updated CLI update command to show table of all packages
- Added KNOWN_PACKAGES, formatAllPackagesTable, getInstallAllCommand
- Marked checkForUpdate() with @deprecated JSDoc

Closes #391

docs/scratchpads/41-plugin-host.md

@@ -10,15 +10,15 @@
 
 - 2026-03-13: session started in worktree; loading gateway/plugin package context.
 - 2026-03-13: implemented initial plugin module, service, interface, and AppModule wiring; pending verification.
-- 2026-03-13: added `@mosaic/discord-plugin` as a gateway workspace dependency and regenerated `pnpm-lock.yaml`.
+- 2026-03-13: added `@mosaicstack/discord-plugin` as a gateway workspace dependency and regenerated `pnpm-lock.yaml`.
 - 2026-03-13: built gateway dependency chain so workspace packages exported `dist/*` for clean TypeScript resolution in this fresh worktree.
 - 2026-03-13: verification complete.
 
 ## Verification
 
-- `pnpm --filter @mosaic/gateway... build` ✅
-- `pnpm --filter @mosaic/gateway typecheck` ✅
-- `pnpm --filter @mosaic/gateway lint` ✅
+- `pnpm --filter @mosaicstack/gateway... build` ✅
+- `pnpm --filter @mosaicstack/gateway typecheck` ✅
+- `pnpm --filter @mosaicstack/gateway lint` ✅
 - `pnpm format:check` ✅
 - `pnpm typecheck` ✅
 - `pnpm lint` ✅