fix(deploy): restore NetFlow to the published compose file, and generate it (v0.23.34-beta)

Closes #121.

The Quick Deploy file was missing NETFLOW_BIND_PORT and the 2055/udp mapping, so
the collector bound inside the container and nothing reached it. NetFlow did
nothing, silently, with an empty traffic page and no error — for everyone
following the path the README tells new users to take.

The report was accurate and understated. docker-compose.ghcr.yml had drifted for
seven weeks, and three closed issues had never reached it:

  * NETFLOW_BIND_PORT and the UDP port — as reported
  * all five POLLER_* tunables — #114, whose fix was "pass the tunables through"
  * the Redis memory ceiling and eviction policy — #116
  * TZ on the postgres service, which nobody had noticed at all

The middle one is the uncomfortable part. Four days ago #114 was closed by
forwarding poller settings that were documented but inert, with a comment saying
setting them "did precisely nothing". On Quick Deploy that remained true, because
one compose file was fixed and the other was not — including the advice given to
that reporter about which knob to turn.

So patching the four gaps would have been treating the symptom. The two files
describe the same system and differ only in where images come from; maintaining
both by hand meant remembering every change twice, and the one forgotten was
always the file no maintainer runs.

docker-compose.ghcr.yml is now generated from docker-compose.yml by
scripts/generate-ghcr-compose.mjs, which performs the two build-to-image swaps
and nothing else. Substitution is textual rather than parse-and-reserialise so
comments survive — the reasoning about Redis eviction is worth more than the two
lines it explains. The file stays committed and browsable, because the README
tells people to curl it directly.

A --check mode runs as the first preflight gate and as its own CI job, both of
which fail when the committed file does not match what the generator produces.
Verified by deleting the NetFlow line and watching the guard reject it, with the
reason and the fix in the failure message.

Reported by @mamb1329, on their first issue.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/ci-preflight.sh

@@ -38,6 +38,11 @@ run() {
 : >/tmp/ci-preflight-failures
 echo "Running CI gates locally (mirrors .github/workflows/ci.yml)"
 
+# The published deployment file is generated. Checking it first because it costs
+# nothing and because drift here is invisible to every maintainer — it only ever
+# breaks the Quick Deploy path that no one on the team runs (#121).
+run "compose: ghcr in sync"  .  node scripts/generate-ghcr-compose.mjs --check
+
 run "backend: lint"        backend  npm run lint
 run "backend: type-check"  backend  npx tsc --noEmit
 run "backend: build"       backend  npm run build