radar-ledger-updatelisted

# 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)