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>

internal/web/handlers_status.go

@@ -8,8 +8,8 @@ import (
 )
 
 // handleStatus renders the server status page: the panel's landing page and the
-// one screen that answers "is the service healthy and will mail be accepted"
-// (phase 13.A). The cheap local checks live in the polled "status_body"
+// one screen that answers "is the service healthy and will mail be accepted".
+// The cheap local checks live in the polled "status_body"
 // fragment; the hostname/PTR lookup and the configuration reload sit outside it,
 // because neither belongs on a five-second timer.
 func (s *Server) handleStatus(w http.ResponseWriter, r *http.Request) {