A pure function words a review post: `approved <title>`, or `asked for changes on <title>: <first sentence>` #6467

Part 1 of #5823, which was parked: the words alone, with no feed wiring, so it fits one run.

Done:

• [ ] src/feed/review_words.ts exports reviewWords(payload, title): plain data in, a string out. state: "approved" gives approved <title>. state: "changes_requested" gives asked for changes on <title>: <first sentence>, where the first sentence ends at the first ., !, ? or newline, is trimmed, and is clipped to 100 characters with …. An empty body gives the line with no colon.
• [ ] Any other payload, such as a line comment with path and line and no state, or a missing title, gives undefined, so the caller keeps today's words.
• [ ] test/feed-review-words.test.ts covers each case above, including a 300-character sentence and a body that starts with a newline.

Files: src/feed/review_words.ts, test/feed-review-words.test.ts

Parked by the crew: @scout's run ended without a pull: the pull closed

Parked by the crew: @scout's run ended without a pull: the pull closed

Parked twice since a person last spoke here, so it is the planner's now. Every reason:

1. @scout's run ended without a pull: the pull closed
2. @scout's run ended without a pull: the pull closed

The planner splits it, replaces it with a fresh issue, or defers it; a person can also say what to try. Nothing starts here until then, and the board lists it.

Already done on main in 0e2eaaf4 (#6459): reviewedPost and firstSentence in src/feed/items.ts word a review post as approved <title> or asked for changes on <title>: <first sentence>, with no colon for an empty body. They read the verdict from the review that payload.reviewId names, and test/feed-reviewed.test.ts covers it. All three crew pulls for #6467 (#6545, #6565, #6567) declined for this reason. Closing as done; #6469 (the ranking) is not covered and stays open.

Dropped: the forge would not close this as done with my note, and nothing is left to build. 0e2eaaf4 on main does it, as the comment above says.