chore(deps): pin patched transitive deps via pnpm.overrides (#42)

## Summary
Direct-dep updates from Renovate could not clear the `scan` gate — 20 vulnerabilities (4 high + 13 moderate + 3 low) lived inside transitive chains pinned by upstream tooling:

- `nx > axios` (8× CVEs), `nx > yaml`, `nx > follow-redirects`
- `@nx/devkit > minimatch > brace-expansion`
- `nestjs-prisma > @angular-devkit/core > ajv`
- `@angular/cli > @modelcontextprotocol/sdk > express-rate-limit > ip-address`
- `@lhci/cli > tmp`

Patched versions exist upstream but the parents pin tighter ranges. Renovate cannot help here — `pnpm.overrides` with the **upper-bound** form (`pkg@<x.y.z`) is the right tool: it forces patched resolutions today and self-expires once a parent legitimately reaches the patched version (the override stops matching).

After overrides: `pnpm audit --audit-level=moderate` → **0 vulnerabilities**.

## Bonus fix
Lint-staged was running prettier on `pnpm-lock.yaml` because the glob `*.yaml` matched. Tightened the glob to `!(pnpm-lock).{...,yaml}` so the lockfile stays under pnpm's own formatting authority.

## Test plan
- [ ] `scan` job goes green on this PR.
- [ ] No regression on `check` (lint/test/build).
- [ ] On the next deps-bump commit (any future Renovate PR rebased), the local pre-commit hook does **not** reformat `pnpm-lock.yaml`.

## Out of scope (separate follow-up PRs)
While testing locally, two pre-existing regressions on `main` surfaced (introduced by recent Renovate major bumps that passed CI through `nx affected` reporting "nothing affected"):

- **TypeScript 6 (PR #33)** — `tsconfig.lib.json` → `TS5101: Option 'baseUrl' is deprecated` on every lib build.
- **ESLint 10 (PR #36)** — `@nx/eslint@22.7.1` plugin can't resolve eslint, project graph fails.

Both deserve their own investigation before we move on to phase-2 chantiers.

---------

Co-authored-by: Julien Gautier <julien.gautier@apf.asso.fr>
Reviewed-on: #42

package.json

@@ -12,7 +12,7 @@
   },
   "private": true,
   "lint-staged": {
-    "*.{ts,tsx,js,jsx,html,scss,css,md,json,yml,yaml}": [
+    "!(pnpm-lock).{ts,tsx,js,jsx,html,scss,css,md,json,yml,yaml}": [
       "prettier --write"
     ]
   },
@@ -30,7 +30,16 @@
       "nx",
       "prisma",
       "unrs-resolver"
-    ]
+    ],
+    "overrides": {
+      "axios@<1.15.2": ">=1.15.2",
+      "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",
+      "tmp@<0.2.4": ">=0.2.4",
+      "yaml@<2.8.3": ">=2.8.3"
+    }
   },
   "prisma": {
     "schema": "apps/portal-bff/prisma/schema.prisma"