Read docs/PROMPT_modules_highlight_symbols.md

Prompt — colour-code reference genes in Coordinated modules + fix missing symbols

Two presentation fixes to the Coordinated-modules table. Verified against the code: _compute_module_ranking (api/app.py ~lines 1244–1457) returns each module as {gene_ids (opaque), size, combined_holdout, coherence, per_gene:[{id,single_gene_metric,rank,total}]} — opaque IDs only, no symbols and no reference-set flag. The table's "—" cells are module genes that were never revealed (e.g. g09647 = LIG1); they resolve fine (HNSC reuses the single colorectal sealed map, its genes a subset), they're just not fetched. Read the current _compute_module_ranking and the modules UI component first. Airgap stays absolute; pytest/tsc after.

1. Flag + colour-code reference-set membership on EVERY module row (so no expanding needed)

• In _compute_module_ranking, resolve the active dataset's reference sets to opaque IDs ONCE (HNSC → p16={CDKN2A}, cell_cycle=the 20-gene set; CRC → MMR, immune). Reuse the existing reference→opaque resolution already used by /diagnostic/full-rank (its reference_marks) / the highlighted-genes table — don't re-implement. This is a bounded reveal of a known small set, not the whole map.
• For each module add ref_sets: list[str] = the reference-set names whose opaque IDs intersect that module's gene_ids (e.g. ["cell_cycle"], ["p16","cell_cycle"], or []).
• Frontend modules table: on each collapsed row, render a small badge per matched set and tint the row using the existing three-way colour scheme (winner accent / p16 deep-gold / cell_cycle muted-amber — the same palette the highlighted-genes table uses). A module containing a p16 or cell_cycle gene must be scannable in the ranked list without expanding it.
• Airgap note: only a boolean membership (derived from the bounded reference reveal) crosses the wire here — no module gene NAMES are sent for the collapsed list.

2. Fix the missing symbols ("—") on expand

• The per-gene symbol is blank because module genes outside the already-revealed subset are never translated. When a module is expanded, reveal that module's gene_ids via the existing /reveal endpoint (bounded — only that module's ~2–5 genes) and show the symbol on each per-gene row. g09647 should then read LIG1.
• Reveal lazily, per expanded module only. Do NOT reveal all modules' genes up front — there are ~2,900 modules and that would approach translating the whole map (airgap violation).
• Keep the per-gene single-gene AUROC / rank already returned; just add the revealed symbol alongside. Where a gene has no rank (not in the diagnostic series) leave its metric blank but still show its symbol.

CONSTRAINTS

• Airgap: reference-membership flag = bounded reference-set reveal; per-module symbols = bounded on-expand reveal. Never translate the full map; the collapsed ranking stays opaque + scores + ref_sets booleans.
• No change to module harvesting, scoring, or sorting — purely additive (ref_sets field + lazy symbol reveal + row colouring).

Checkpoint

• Collapsed module rows show a p16 / cell_cycle (or MMR / immune) badge and matching row tint wherever the module contains such a gene — visible without expanding.
• Expanding any module shows a symbol for every gene (e.g. LIG1), no "—".
• Ranking payload stays opaque + ref_sets booleans; symbols revealed only for expanded modules; airgap tests green; tsc/pytest clean.