fix(ci): move grpc-tools to optionalDependencies (revert NODE_OPTIONS attempt) (#200)

## Summary

The `NODE_OPTIONS=--use-system-ca` workaround merged in #199 did not clear the CI install failure — the runner still rejects the TLS chain to `node-precompiled-binaries.grpc.io`. Either the runner's OS CA bundle is missing the same intermediate Node's bundled set is missing, or `--use-system-ca` does not propagate down to the `node-fetch@2` that `node-pre-gyp` uses. Without runner shell access the exact reason is not worth chasing.

Switch angle: **the protoc binary `grpc-tools` downloads is never used in CI**. The generated TypeScript stubs in `apps/portal-bff/src/grpc/gen/` are committed per [ADR-0024](docs/decisions/0024-ai-service-relay-grpc-sse-bridge.md) §"Sub-decision 3 — vendored protos", so CI only needs to type-check them; protoc only runs when a developer regenerates from `apps/portal-bff/src/grpc/proto/apf-ai/*.proto`.

This PR moves `grpc-tools` from `devDependencies` to `optionalDependencies`. Per pnpm semantics, when an optional dep's install (including postinstall) fails, pnpm logs a warning and the overall install completes. CI's `pnpm install --frozen-lockfile` therefore succeeds even when the binary cannot be fetched; developer machines (where TLS validates) install grpc-tools normally and `pnpm grpc:codegen` works unchanged.

## What lands

- `package.json` — `grpc-tools: "^1.13.0"` moves out of `devDependencies` and into a new `optionalDependencies` block. The entry in `pnpm.onlyBuiltDependencies` stays — it controls whether pnpm *attempts* the postinstall, not whether failure is fatal. Local installs (where TLS works) still run the postinstall and download the binary.
- `pnpm-lock.yaml` — refreshed; the lockfile reflects the new optional-dep classification. No version changes to anything else.
- `.gitea/workflows/ci.yml` — revert the workflow-level `env: NODE_OPTIONS: --use-system-ca` block added in #199. Did not help; left in place it would be a misleading "this is supposed to fix CI TLS" signpost.
- `.gitea/workflows/docs-site.yml` — same revert.

## Notes for the reviewer

- **Why `optionalDependencies` is the right primitive.** pnpm 10 documents the contract: a package listed in `optionalDependencies` is *attempted*; if the install fails for any reason (platform mismatch, postinstall script error, network failure), the failure is logged and the overall command continues. That maps exactly to what this PR needs: try in CI, fail gracefully, succeed locally.
- **Why not remove `grpc-tools` from `pnpm.onlyBuiltDependencies` instead.** Removing it from the allowlist tells pnpm not to even *try* the postinstall, which would also fix CI. But it would also break the developer workflow — locally, the protoc binary would never download, and `pnpm grpc:codegen` would fail. The dev would have to manually trigger the build (`pnpm approve-builds` then `pnpm rebuild grpc-tools`), or worse, devs would commit accidental `package.json` mutations from `approve-builds`. The `optionalDependencies` route keeps the local DX identical.
- **Why revert the workflow `env:` blocks.** They do not help here, and leaving them in place implies that `--use-system-ca` is the canonical fix for this class of failure — which it is *not*, at least not for this runner / this CDN. If a future native dep hits a similar wall and `--use-system-ca` *does* fix it for that case, the env var lands in a focused PR with a real validation. Carrying it now as a "maybe useful later" workaround is noise.
- **Codegen workflow on developer machines.** Unchanged. `pnpm install` runs the postinstall (TLS validates locally), the protoc binary lands in `node_modules/`, `pnpm grpc:codegen` regenerates stubs. The only visible difference is a one-line `WARN GET_RESOLVED_FROM_REGISTRY ...` if a contributor ever encounters the same TLS failure locally (e.g., on a corporate-proxied machine) — pnpm will mark grpc-tools as failed-optional and the rest of the install proceeds; the dev can then debug their own network without blocking the whole repo.
- **Idempotence with CI's `--frozen-lockfile`.** The lockfile change is small (re-classifies grpc-tools from `dev` to `optional`) and lands in this PR. After merge, CI runs against the new lockfile; no further coordination needed.

## Test plan

- [x] `pnpm install` locally — clean, grpc-tools postinstall runs successfully (TLS validates), protoc binary present.
- [x] `pnpm grpc:codegen` — regenerates the TypeScript stubs identically (no diff in `apps/portal-bff/src/grpc/gen/`).
- [x] `pnpm nx run-many -t lint test build -p portal-shell,portal-admin,portal-bff,shared-ui,shared-charts` — all five projects green.
- [ ] **CI green on this PR's first run.** The validation that matters: `pnpm install --frozen-lockfile` completes despite grpc-tools' postinstall failure; `ci:check` runs to completion.
- [ ] Spot-check of post-merge CI runs over the next few days to confirm the warning is recurring (expected) and the install never fails (the contract).

## What's next

- If the CI behaviour is what this PR predicts (warning instead of failure), no further action required.
- If `optionalDependencies` does not work as documented (highly unlikely, but possible if the pnpm version has a regression), the fallback is to drop `grpc-tools` from `pnpm.onlyBuiltDependencies` and add a small dev-onboarding note. One-line change away.
- Long-term cleanup: if a future PR migrates the codegen step to a Docker-based tool (`buf`, system protoc) the optional-dep entry can be removed entirely. Out of scope here.

---------

Co-authored-by: Julien Gautier <julien.gautier@apf.asso.fr>
Reviewed-on: #200

.gitea/workflows/ci.yml

@@ -11,18 +11,6 @@ on:
   push:
     branches: [main]
 
-# Node 24's bundled CA set does not include every intermediate the
-# self-hosted runner's network path serves (the precompiled-binary
-# CDN behind grpc-tools is the first surface where this surfaced).
-# `--use-system-ca` tells Node to consult the OS CA store in
-# addition to its bundled set — supported since Node 22 and the
-# documented Node-team fix for exactly this class of TLS-chain
-# rejection. The runner image (`catthehacker/ubuntu:act-22.04` per
-# ADR-0015) carries the standard Ubuntu `ca-certificates` bundle,
-# which validates the impacted chains.
-env:
-  NODE_OPTIONS: --use-system-ca
-
 jobs:
   check:
     runs-on: [self-hosted, on-prem]

.gitea/workflows/docs-site.yml

@@ -28,13 +28,6 @@ on:
       - 'pnpm-lock.yaml'
       - '.gitea/workflows/docs-site.yml'
 
-# See `.gitea/workflows/ci.yml` for the rationale — Node 24's
-# bundled CA set rejects some chains the runner's OS trust store
-# validates, and `--use-system-ca` (Node ≥ 22) tells Node to
-# consult the OS CA bundle alongside its own.
-env:
-  NODE_OPTIONS: --use-system-ca
-
 jobs:
   build:
     runs-on: [self-hosted, on-prem]

package.json

@@ -111,7 +111,6 @@
     "eslint": "^9.8.0",
     "eslint-config-prettier": "^10.0.0",
     "eslint-plugin-playwright": "^1.6.2",
-    "grpc-tools": "^1.13.0",
     "husky": "^9.1.7",
     "jest": "^30.0.2",
     "jest-environment-node": "^30.0.2",
@@ -196,5 +195,8 @@
     "pino-http": "^11.0.0",
     "reflect-metadata": "^0.2.0",
     "rxjs": "~7.8.0"
+  },
+  "optionalDependencies": {
+    "grpc-tools": "^1.13.0"
   }
 }

pnpm-lock.yaml

@@ -356,9 +356,6 @@ importers:
       eslint-plugin-playwright:
         specifier: ^1.6.2
         version: 1.8.3(eslint@9.39.4(jiti@2.7.0))
-      grpc-tools:
-        specifier: ^1.13.0
-        version: 1.13.1(encoding@0.1.13)
       husky:
         specifier: ^9.1.7
         version: 9.1.7
@@ -434,6 +431,10 @@ importers:
       webpack-cli:
         specifier: ^5.1.4
         version: 5.1.4(webpack@5.106.2)
+    optionalDependencies:
+      grpc-tools:
+        specifier: ^1.13.0
+        version: 1.13.1(encoding@0.1.13)
 
   libs/shared/tokens:
     dependencies:
@@ -13769,6 +13770,7 @@ snapshots:
     transitivePeerDependencies:
       - encoding
       - supports-color
+    optional: true
 
   '@mermaid-js/mermaid-mindmap@9.3.0':
     dependencies:
@@ -17052,7 +17054,8 @@ snapshots:
     dependencies:
       argparse: 2.0.1
 
-  abbrev@3.0.1: {}
+  abbrev@3.0.1:
+    optional: true
 
   abbrev@4.0.0: {}
 
@@ -19242,6 +19245,7 @@ snapshots:
     transitivePeerDependencies:
       - encoding
       - supports-color
+    optional: true
 
   hachure-fill@0.5.2: {}
 
@@ -20863,6 +20867,7 @@ snapshots:
   nopt@8.1.0:
     dependencies:
       abbrev: 3.0.1
+    optional: true
 
   nopt@9.0.0:
     dependencies: