fix(deps): revert TS6/ESLint10/webpack-cli7 majors and gate future majors (#43)

## Summary
Three Renovate major bumps merged silently because `nx affected` doesn't see deps-only PRs as affecting any project — CI passed trivially, the breakage only surfaced when `nx run-many` was run locally:

- **TypeScript 5→6** (#33) — `tsconfig.lib.json` fails with `TS5101: Option 'baseUrl' is deprecated`. Revert to 5.9.x.
- **ESLint 9→10** (#36) — `@nx/eslint@22.7.1` not compatible: project graph fails with "Unable to find eslint". Revert eslint, `@eslint/js`, `jsonc-eslint-parser`, `eslint-plugin-playwright` to ESLint-9-compatible versions.
- **webpack-cli 5→7** (#34) — webpack-cli 7 removed the `--node-env=production` flag Nx generates. Revert to 5.x.

Bonus side-fix: the `ajv@<8.18.0` override added in #42 was over-broad and was forcing ESLint's bundled ajv to v8 (incompatible with ESLint 9's option contract). Narrow the override to `@angular-devkit/core>ajv@<8.18.0` so only the targeted nestjs-prisma chain is bumped.

## Prevention — gate majors behind the dependency dashboard

Add a Renovate `packageRule` with `dependencyDashboardApproval: true` for `matchUpdateTypes: ["major"]`. Renovate stops auto-creating PRs for majors; they appear as checkboxes in the dashboard issue, and only get a PR after a human ticks the box (presumably after reading the changelog and confirming Nx-plugin / Angular / NestJS readiness).

This is the surgical fix for the gap. The deeper fix (making `nx affected` correctly mark all projects as affected on package.json changes) is a separate investigation worth doing later — but the dashboard gate prevents the same trap regardless.

## Verification
Locally on this branch:
- `pnpm exec nx run-many -t lint test build --parallel=2` → ✓ 8 projects pass.
- `pnpm audit --audit-level=moderate` → 0 vulnerabilities.

## Test plan
- [ ] `check` job goes green on this PR (would have caught the regressions if `nx affected` were broader).
- [ ] After merge, the next Renovate run does not create new PRs for any major (TS, eslint, webpack-cli, etc.).
- [ ] Any pending major in the dashboard issue still appears, but only as a checkbox awaiting approval.

## Out of scope (follow-up)
Investigate why `nx affected` misses package.json-only changes. Likely a missing entry in `nx.json` `namedInputs` (`default`) or `targetDefaults`. Worth its own focused PR; the dashboard gate is the conservative fix in the meantime.

---------

Co-authored-by: Julien Gautier <julien.gautier@apf.asso.fr>
Reviewed-on: #43

package.json

@@ -33,7 +33,7 @@
     ],
     "overrides": {
       "axios@<1.15.2": ">=1.15.2",
-      "ajv@<8.18.0": ">=8.18.0",
+      "@angular-devkit/core>ajv@<8.18.0": ">=8.18.0",
       "brace-expansion@<5.0.5": ">=5.0.5",
       "follow-redirects@<1.16.0": ">=1.16.0",
       "ip-address@<10.1.1": ">=10.1.1",
@@ -55,7 +55,7 @@
     "@angular/language-service": "~21.2.0",
     "@commitlint/cli": "^20.5.3",
     "@commitlint/config-conventional": "^20.5.3",
-    "@eslint/js": "^10.0.0",
+    "@eslint/js": "^9.8.0",
     "@lhci/cli": "^0.15.1",
     "@nestjs/schematics": "^11.0.0",
     "@nestjs/testing": "^11.0.0",
@@ -85,15 +85,15 @@
     "@vitest/coverage-v8": "~4.1.0",
     "@vitest/ui": "~4.1.0",
     "angular-eslint": "^21.2.0",
-    "eslint": "^10.0.0",
+    "eslint": "^9.8.0",
     "eslint-config-prettier": "^10.0.0",
-    "eslint-plugin-playwright": "^2.0.0",
+    "eslint-plugin-playwright": "^1.6.2",
     "husky": "^9.1.7",
     "jest": "^30.0.2",
     "jest-environment-node": "^30.0.2",
     "jest-util": "^30.0.2",
     "jsdom": "^29.0.0",
-    "jsonc-eslint-parser": "^3.0.0",
+    "jsonc-eslint-parser": "^2.1.0",
     "lint-staged": "^17.0.0",
     "nx": "22.7.1",
     "postcss": "^8.5.12",
@@ -103,11 +103,11 @@
     "ts-jest": "^29.4.0",
     "ts-node": "10.9.2",
     "tslib": "^2.3.0",
-    "typescript": "~6.0.0",
+    "typescript": "~5.9.2",
     "typescript-eslint": "^8.40.0",
     "vite": "^8.0.0",
     "vitest": "^4.0.8",
-    "webpack-cli": "^7.0.0"
+    "webpack-cli": "^5.1.4"
   },
   "dependencies": {
     "@angular/common": "~21.2.0",