Route A driver pins a stale Chronicle feed hash and refuses to run on current main #1220

tools/route_a/route_a.sh hardcodes FEED_SHA=b85437390021777e746f507c5890305496baf5fc7f2c78ba08ddb090f4839801 and checks that packages/microcosm-build/src/microcosm/build/us/chronicle_feed.json at the build commit pins that facts_sha256; a mismatch adds a COMMIT_BLOCKER ("the release tool would refuse the feed").

Since the #940 re-pin (ea8940de2, merged with #1102), chronicle_feed.json on main pins facts_sha256 965a29ac9458edb58a05184917ee4a19772fd3dc7b4588db6eb6da5803641aac (Chronicle 51aa40fd28e2ca81937752515e773d123fecfb71, 40,178 rows). So the driver refuses the next certified build on current main, the Route A rerun in decision d1386.

Fix: point the driver's FEED / FEED_SHA (and BASE_LEDGER_FACTS default) at the feed main pins (docs/us-chronicle-feed-repin.md, tools/build_us_chronicle_feed.py), re-check the driver's other pinned inputs against main, and ideally derive the expected hash from chronicle_feed.json so the two cannot drift. Verify with the driver's offline pin check only; no build.

Found during the frame-structure audit behind #1212–#1216.