docs/chore: Phase 1 doc/code hygiene (code-review.md § Phase 1)

Removes ~30 stale "Phase N" / historical-staging comment references from
code and shell scripts now that v1.0 is done; fixes a stale dashboard
comment claiming applications/send-log were unimplemented; adds a CSRF ADR
to security.md documenting the Origin-check-over-tokens decision; resolves
docs/logo in roadmap.md (directory doesn't exist, criterion already met);
adds a gofmt -l check to CI so unformatted Go fails the build.

The known-limitations write-up for the log-tailer offset gap (the other
Phase 1 item) was already present in architecture.md § Log tailer, so no
change was needed there.

gofmt/go vet/go test clean on both Go modules (main + test/e2e), verified
on the dev server.

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

.github/workflows/test.yml

@@ -16,6 +16,15 @@ jobs:
           go-version: "1.26"
           cache: true
 
+      - name: Format
+        run: |
+          fmt="$(gofmt -l .)"
+          if [ -n "$fmt" ]; then
+            echo "$fmt"
+            echo "gofmt needed on the files above; run 'gofmt -w .'"
+            exit 1
+          fi
+
       - name: Vet
         run: go vet ./...