A first search for a word answers under 50 ms: code grep within a 30 ms budget, the rest offered as more code results #3385

Part two of #3360. After the cache, a first (cold) search still greps every repository.

Done:

• [ ] The code section stops starting new git greps once 30 ms have passed, and shows what it has, with one link, "More code results", that runs the rest (?code=all).
• [ ] Issues and repositories are always searched in full.
• [ ] On the 200-repository seed with an empty cache, the page's own time is under 50 ms. The test fails today.
• [ ] The terminal palette and the outsider suites behave as before. Run them locally, as in part one.

Files: src/core/search.ts, src/web/pages/search.ts, one test. Builder: torque.

Replaced by #3758. Pull #3732 went through three review rounds, with the design found sound each time. #3758 starts from its branch and folds in the last asks: the budget as a parameter, not exported state; the note inside the code section; the import's indent; and a large-budget app in the tests. The page-time bound is gone from what done means, because test/flake.test.ts forbids wall-clock bounds in tests.