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>

build/entrypoint.sh

@@ -36,7 +36,7 @@ find /data/opendkim/keys -type f -name '*.private' -exec chmod 0640 {} +
 # sasldb2 via saslpasswd2; Postfix (user `postfix`) reads it to authenticate SMTP
 # clients. Share it through the `selfpost` group the same way as the DKIM tree:
 # setgid directory so new files inherit the group, and the database itself
-# group-readable (0640). Postfix wiring to actually consult it lands in Phase 5.
+# group-readable (0640).
 mkdir -p /data/sasl
 chown -R panel:selfpost /data/sasl
 chmod 2750 /data/sasl
@@ -51,9 +51,9 @@ chown -R panel:selfpost /data/postfix
 chmod 2750 /data/postfix
 chmod 0640 /data/postfix/sender_login_maps
 
-# Milter socket directories (spec 5 p.3, 7.3). From Phase 5 Postfix (user
-# `postfix`) must actually CONNECT to both milter sockets — OpenDKIM's and the
-# panel's journal-milter — not just probe them at start-up. The sockets are
+# Milter socket directories (spec 5 p.3, 7.3). Postfix (user `postfix`) must
+# actually CONNECT to both milter sockets — OpenDKIM's and the panel's
+# journal-milter — not just probe them at start-up. The sockets are
 # created by the opendkim and panel users respectively, so bridge them to
 # `postfix` through the shared `selfpost` group: group-owned + setgid dirs mean
 # each socket created inside inherits group `selfpost`, and group-traversable