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/static/panel.css

@@ -1,6 +1,6 @@
 /* Panel stylesheet. It lives in a file rather than in a <style> block in the
    layout so the panel's Content-Security-Policy can be a plain
-   "default-src 'self'" with no inline-style exemption (phase 14.A). Any rule
+   "default-src 'self'" with no inline-style exemption. Any rule
    added here must therefore stay here: an inline style="..." attribute in a
    template is blocked by that policy and silently does nothing. */