fix(T-33): alert when the curator matches none of the repos it was given

[DamengRandom]

Closes #27

The bug

An empty curation was logged at info level as a routine skip:

⏭️ No repos curated — skipping send and save.

It cannot be a routine skip. collectTopRepos returns null when nothing is trending and never an empty array, so curateOrNotify always receives at least one repo. An empty result can only mean the curator matched none of them — total failure, classified as a non-event.

The failure comes from mergeSummaries, which drops any repo the model did not echo back by exact name. Only prose in the prompt asks for that, and withStructuredOutput keeps the response schema-valid either way — so the retry loop never saw it. curateNode retries on a JSON parse error or a schema mismatch, and this is neither.

Net effect on an unattended morning run: no digest, no rows, no alert, no retry — and it looks identical in the logs to a genuinely quiet day.

The fix

An empty curation is now a retryable error carrying the exact name the model failed to match, so the retry and alert machinery that already exists applies to it. One condition in curateNode; no new plumbing.

The dead !curated.length branch in curateOrNotify is removed, since runCuratorGraph now returns null or a non-empty array. The comment that asserted the false premise is corrected.

Verification

Ran the real mergeSummaries and the real runCuratorGraph against three ordinary LLM reformattings:

model returned	before	after
next.js (owner dropped)	1 attempt, silent skip	2 attempts → curated=null → alert
Vercel/Next.js (title-cased)	1 attempt, silent skip	2 attempts → curated=null → alert
" vercel/next.js " (padded)	1 attempt, silent skip	2 attempts → curated=null → alert
exact (control)	1 attempt, curated	1 attempt, curated — unchanged

Recovery also works. When the model corrects itself on the retry, the digest goes out instead of vanishing:

retry feedback → curator returned summaries for none of the 2 repos it was given — repo_name must match exactly...
attempts=2  curated=2

• pnpm test — 73 pass (2 new), pnpm tsc and pnpm format:check clean

Deliberately not in scope

A partial mismatch still shrinks the digest silently. Issue #27 explicitly excludes it, and it may well be acceptable behaviour — worth deciding separately rather than bundling here.

🤖 Generated with Claude Code