feat(about): show build commit next to the app version

Settings > About now renders "<version> (<short-sha>)" with the full
SHA in the tooltip, so bug reports from test and nightly builds
identify the exact commit. The commit is injected at CI build time into
apps/web/src/environments/build-commit.ts (same placeholder pattern as
the TMDB key inject); PR builds use the real head SHA instead of the
ephemeral merge commit. Local/dev builds keep the plain version.

The semver version itself deliberately stays untouched: a "-sha"
suffix would flip electron-updater into prerelease mode and leak into
installer/artifact version fields.

Requested by WolfganP in #1202.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/build-and-make.yaml

@@ -396,6 +396,14 @@ jobs:
                   TMDB_API_KEY: ${{ secrets.TMDB_API_KEY }}
               run: node tools/tmdb/inject-tmdb-key.mjs
 
+            - name: Inject build commit
+              # Shows "<version> (<sha>)" in Settings > About so bug reports
+              # from test builds identify the exact commit. PR builds use the
+              # head SHA — github.sha would be the ephemeral merge commit.
+              env:
+                  BUILD_COMMIT: ${{ github.event.pull_request.head.sha || github.sha }}
+              run: node tools/build/inject-build-commit.mjs
+
             - name: Build frontend
               run: pnpm nx build web --skip-nx-cache