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/gateway-security-20260313.md

@@ -46,7 +46,7 @@ Complete the remaining gateway security hardening work:
 
 ## Verification Log
 
-- `pnpm --filter @mosaic/gateway test -- src/chat/__tests__/chat-security.test.ts src/__tests__/resource-ownership.test.ts`
+- `pnpm --filter @mosaicstack/gateway test -- src/chat/__tests__/chat-security.test.ts src/__tests__/resource-ownership.test.ts`
   - Red: failed on socket session reshaping and DTO role/length mismatches.
   - Green: passed with 3 test files and 20 tests passing.
 - `pnpm typecheck`