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/templates/layout.html

@@ -15,7 +15,7 @@
 {{/* Unless told otherwise, htmx injects a stylesheet element of its own into
      the head for the request-indicator classes. The panel uses no
      hx-indicator, and that injected element would be the one thing the
-     Content-Security-Policy (phase 14.A) has to make an exception for, so it
+     Content-Security-Policy has to make an exception for, so it
      is switched off here. */}}
 <meta name="htmx-config" content='{"includeIndicatorStyles":false}'>
 <script src="/static/htmx.min.js" defer></script>