chore: upgrade to Angular 22 + TypeScript 6.0, extend compat matrix to 18–22

[CodeAndWeb]

Brings the dev workspace (library build toolchain + test-app) from Angular 21.2.8 → 22.0.0 and extends the cross-version compat matrix to cover Angular 18–22. The published library version (18.0.0-rc.3) and the @angular/core >=18 peer floor are unchanged — this is a toolchain upgrade, not a release.

Workspace upgrade

• ng update to @angular/* ^22, @angular/cli/@angular/build/@angular/compiler-cli/ng-packagr ^22, angular-eslint ^22; pinned typescript ~6.0, typescript-eslint ^8.61, zone.js ~0.16.
• Kept the schematic's behavior-preserving migrations, but made them cross-version safe so the shared source still compiles under Angular 18–21 in the matrix:
  • demo components use ChangeDetectionStrategy.Default (identical to v22's Eager, but exists in all versions) instead of the v22-only Eager;
  • withXhr() kept only in the test-app bootstrap; dropped from the http-loader specs (inert there under provideHttpClientTesting(), and the symbol doesn't exist on older Angular).
• Reverted the migration's extendedDiagnostics suppressions — the library builds clean with nullishCoalescing/optionalChain diagnostics on.
• Lint: the shipped libraries lint clean; one block-directive spec now signal-drives its property-change test so it passes under the v22 OnPush default (no CD override, no suppression). Honored the ^_ unused-var convention in eslint config (removed one inline disable). Added a best-effort lint target + config for test-app.

Compat matrix

• Extended to a18, a19, a20, a21, latest(=22); dropped a16 (below the >=18 floor).
• test-and-build-for-all.sh: lint is best-effort/non-fatal and skipped where no lint target exists; config restored unconditionally via trap restore_latest EXIT.
• Added compat/consume/ — an artifact-consumability gate that type-checks the packed v22/TS6 .d.ts against TS 5.5–5.9 with skipLibCheck:false.

Verification (all green)

• build-all + test-ci (448 tests) + lint + ng build test-app on Angular 22.
• Manual smoke check: language switching updates correctly.
• Full matrix: build + test green on Angular 18 / 19 / 20 / 21 / 22.
• Consumability gate green for a18–a21 — the v22 .d.ts is consumable down to the >=18 peer floor.
• Lint best-effort: a21/latest clean; a20 fails only on a typescript-eslint@8.2.0 rule-loading skew (non-fatal, documented).

Follow-up (not in this PR)

Matrix-script reproducibility (corepack prepare pnpm@latest + lockfile deletion) is tracked separately; this PR adds packageManager pins to a19/a20 as the minimal unblock.

🤖 Generated with Claude Code