ci: raise golangci-lint to 30m, test to 40m, job ceiling to 50m (mc#1099)

Cold runner reality on staging:
  fetch-depth:0 clone     ~5-10m
  Go toolchain            ~5-10m
  go mod download         ~2-5m
  go build + go vet      ~2-5m
  golangci-lint install  ~2-5m
  golangci-lint run      ~2-5m  (project .golangci.yaml disables errcheck)
  go test               ~16-20m  (cold cache)
  = up to 50m total

Changes vs origin/staging ci.yml:
  - golangci-lint --timeout: 3m → 30m (override project ceiling)
  - go test -timeout:         10m → 40m
  - job timeout-minutes:       15m → 50m

No --no-config added (project .golangci.yaml disables errcheck
correctly; v2.x errcheck finds 30+ violations in test files).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -145,10 +145,9 @@ jobs:
     # the diagnostic step with its own continue-on-error: true (line 203).
     # Flip confirmed by CI / Platform (Go) status = success on main HEAD 363905d3.
     continue-on-error: false
-    # Job-level ceiling. The go test step below runs with a per-step 10m timeout;
-    # this cap catches any step that leaks past that. Set well above 10m so
-    # the per-step timeout is the active constraint.
-    timeout-minutes: 15
+    # mc#1099: job-level ceiling raised to 50m. Cold runner: golangci-lint
+    # (~15-20m pre-lint setup + ~5m lint) + test suite (~16-20m) = ~36-45m.
+    timeout-minutes: 50
     defaults:
       run:
         working-directory: workspace-server
@@ -174,7 +173,9 @@ jobs:
         run: go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.12.2
       - if: always()
         name: Run golangci-lint
-        run: $(go env GOPATH)/bin/golangci-lint run --timeout 3m ./...
+        # mc#1099: cold runner takes ~15-20m pre-lint + ~5m lint. Override
+        # workspace-server/.golangci.yaml 3m ceiling with --timeout 30m.
+        run: $(go env GOPATH)/bin/golangci-lint run --timeout 30m ./...
       - if: always()
         name: Diagnostic — per-package verbose 60s
         run: |
@@ -193,11 +194,10 @@ jobs:
         continue-on-error: true
       - if: always()
         name: Run tests with race detection and coverage
-        # Explicit timeout: cold runner cache causes OOM kills at ~4m39s on the
-        # full ./... suite with race detection + coverage. A 10m per-step timeout
-        # lets the suite complete on cold cache (~5-7m) while failing cleanly
-        # instead of OOM-killing. The job-level timeout (15m) is a backstop.
-        run: go test -race -timeout 10m -coverprofile=coverage.out ./...
+        # mc#1099: cold runner test suite takes ~16-20m with race detection.
+        # Raised 10m → 40m so the suite completes on cold cache. The job-level
+        # timeout (50m) is the backstop.
+        run: go test -race -timeout 40m -coverprofile=coverage.out ./...
 
       - if: always()
         name: Per-file coverage report