Add friendly scrape names and a completeness check

docs/testing.md

@@ -61,6 +61,20 @@ The mock also covers tiers, continuation, polls, reactions, and the action log.
 with `set_puppet_config` before a test. Inject a reaction with
 `TEST_TRIGGER_REACTION=1 TEST_REACTION_MESSAGE_ID=msg-1 TEST_REACTION_EMOJI="1️⃣" pnpm test:trigger`.
 
+## Scrape completeness
+
+`pnpm verify:scrapes` (from `poc/`) walks every scrape index and reports whether the walk
+plausibly reached the start of the source:
+
+- state is `done`, no `lastError`, and the message count is non-zero
+- the message count matches the recorded Discord search total when there is one
+- the oldest message is close to the source's creation time, derived from the channel ID
+  snowflake (`--grace <days>` sets the allowance, default 60)
+
+The age check is a heuristic: a channel can sit empty after creation, and a ranged scrape is
+expected to stop early. A flagged scrape that a later full walk of the same source supersedes is
+reported as `old` rather than a problem. Exit code is 1 when a scrape is genuinely incomplete.
+
 ## Web UI smoke test
 
 The web UI starts with the daemon. The mock core is enough for this test.