Radar ledger update

Update the ledger safely

TRENDS.md is the single source of truth and later sessions parse it. The structure is a contract.

File contract (do not change)

• Header: # Trend ledger — AI Radar, then Last updated: YYYY-MM-DD, then the stage legend.
• Sections, in this order: ## Active trends, ## observation_queue, ## source_rotation, ## strategy_notes, ## study_shelf, ## calibration.
• ## source_rotation and ## calibration are POINTER stubs only: their real append-only content lives in logs/source_rotation.md and logs/calibration.md respectively. Keep the two stub headers (the section order is the contract) but NEVER inline log lines back into TRENDS.md — appends go to the logs/ files.
• Trend block: ### [id: slug-NNN] Title with fields alias, optional pinned: true, stage, confidence, first_observed, last_evidence, evidence: (list), notes:.
• Evidence line: - YYYY-MM-DD — URL — one line of context.

Rules

• Match findings to existing trends via id and alias before creating a new trend. New trends take the next free NNN and start at seed or emerging.
• ROUTE a captured primary, don't default to "queue it": (a) if it lands on an EXISTING trend's axis, append it as EVIDENCE there — a single primary suffices for an existing trend; the ≥3-source bar is only for CREATING a trend; (b) if the queue now holds ≥3 independent groups on one untracked sub-theme, promote that cluster to a seed trend; (c) else it stays a queue item. Leaving an on-axis primary in the queue (hoarding evidence) or a named primary in report prose only is a routing failure.
• Max 10 evidence items per trend — drop the oldest. Keep last_evidence equal to the newest evidence date.
• Stage moves: at most ONE stage up per trend per day, only on new independent evidence, justified in notes. Demotions are always allowed. 21+ days without evidence → dormant; at 45+ days the weekly pass moves the entry to ARCHIVE.md as a one-line post-mortem.
• Pinned trends (pinned: true): NEVER auto-archived, no matter how long without evidence — they are the curator's standing-watch axes. They still follow the normal stage rules, INCLUDING going dormant when quiet (the ledger stays truthful about activity); they simply never leave the board. Only the curator adds/removes a pin (or the agent proposes it via amendment).
• observation_queue items are dated and marked "unverified" unless opened. It is a WORKING SET (signals pending verification), not a knowledge store — keep it bounded to a soft cap of ~25 live items by a CAP-DRIVEN burndown that runs every session, including quiet/no-evidence passes: while the queue is OVER the cap, resolve the oldest items toward the cap that run regardless of what the scan found; at/under the cap it stops on its own (resolve only the 1–2 oldest if stale). This is owed every run, never deferred to the weekly — a no-evidence pass is not a no-op for the queue. Items leave ONLY by resolution: promoted to a trend (the signal is captured there) or dropped with a one-line reason in the day's/week's report (write-once, permanent). NEVER silently delete — because every removal is either a promotion or a recorded drop, shrinking the queue loses no knowledge. Re-date an item only if it is genuinely still worth watching.
• Append one dated line per session to logs/source_rotation.md (the coverage log; not the TRENDS.md stub). Append dated corrections to the strategy_notes section of TRENDS.md; never delete curator entries.
• study_shelf: newest first, format date — [name](url) — one line of why; single-artifact items allowed (the trend bar does not apply), opened primary sources only.
• calibration (now logs/calibration.md) is append-only and written by weekly runs only (see the radar-self-eval skill); daily runs never touch it.
• Update the Last updated line. Keep everything in English.

Validate before commit

grep -n '^## ' TRENDS.md
# expected, in order: Active trends, observation_queue, source_rotation, strategy_notes, study_shelf, calibration
grep -c '^### \[id: ' TRENDS.md          # trend count matches expectations
grep -nE '^  - [0-9]{4}-[0-9]{2}-[0-9]{2} — ' TRENDS.md | head -3   # evidence format
grep -n '^Last updated:' TRENDS.md       # date is today
# the two externalized logs must exist and only grow (append-only):
test -f logs/source_rotation.md && tail -1 logs/source_rotation.md | head -c 80
test -f logs/calibration.md && tail -1 logs/calibration.md | head -c 80
# TRENDS.md must NOT have regrown a log body (the stubs stay one-line pointers):
awk '/^## source_rotation/{n=0} /^## strategy_notes/{print "rotation stub lines:", n} {n++}' TRENDS.md

If a check fails, fix the file before committing. Commit and push per the conventions in AGENTS.md.