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>

cmd/panel/httpserver.go

@@ -16,8 +16,8 @@ import (
 )
 
 // serveHTTP runs the control-panel HTTP server until ctx is cancelled, using
-// the database handle shared by all roles. From Phase 2 this serves the real
-// setup, login and authenticated panel surface (spec 7.6).
+// the database handle shared by all roles: setup, login and the authenticated
+// panel surface (spec 7.6).
 func serveHTTP(ctx context.Context, cfg config, st *store.Store) error {
 	// Applications own the SASL accounts and the Postfix sender map; the domain
 	// service delegates to them when a domain (and its applications) is deleted.