Read docs/PROMPT_enable_search.md

Prompt — enable the Search operator (turn on the full DSL)

Search is currently gated off by default; turn it on so the engine can use the whole DSL. Verified the exact location. Airgap untouched (Search operates on opaque IDs). pytest + tsc after.

1. Enable Search injection (engine_v2/synthesize.py)

DEFAULT_RATES (~lines 51-55) has "search": 0.0. Set it to a modest non-zero rate so Search appears in the population without dominating or blowing up runtime:

• "search": 0.05 Keep Search's existing safety caps (k ≤ 4 selected, ≤ 200 candidate columns) — those bound each Search's cost; don't remove them. The injection gate at ~line 109 (rates["search"] > 0) already does the rest. Leave the other rates (split/fitapply/effect) unchanged.

2. Update the "Search" tile copy (web/app/Lab.tsx, DSL vocabulary)

The Search tile says "Nested feature search — available but off by default." Change it to reflect that it's now on, e.g. "Nested feature search — runs a small gene-ranking inside the program (bounded: ≤4 genes from ≤200 columns)." Remove the "off by default" wording.

3. (Recommended) a per-run toggle so it can be turned off for speed

Search is the one heavy operator — every Search node runs an inner gene-ranking, so runs will be slower. To keep control:

• RunRequest gains enable_search: bool = True. The _worker maps enable_search=False → pass a rates override with search: 0.0; True → use the default (0.05). (Thread the rates override into run_v2_pipeline* → synthesize, which already accepts a rates dict, ~line 212/220.)
• Frontend: a Parameters checkbox "Enable Search operator" (default ON). Tooltip: "Lets programs run a small built-in gene-search (bounded). Powerful but the heaviest operator — turn off for faster runs."
• If this part is too much scope, at minimum do Parts 1-2 (enable by default); the toggle is the nice-to-have.

CONSTRAINTS

• Airgap untouched — Search ranks opaque columns, no gene names.
• Caps stay (k ≤ 4, ≤ 200 cols) so cost is bounded.
• Note for the user: expect somewhat slower runs now that Search can fire; lower its rate or use the toggle if it's too slow.

Checkpoint

• DEFAULT_RATES["search"] = 0.05; an HPV coherence run now shows Search used > 0× in the DSL-vocabulary operator-usage panel.
• The Search tile no longer says "off by default".
• (If done) an "Enable Search operator" toggle (default ON) flips its rate.
• pytest green; airgap untouched; tsc clean.