refactor(coding-agent): remove the test-only daemon-lookup seam from main.ts

[snimu]

What was wrong

main.ts's interactive-startup wrapper accepted an optional injected daemon-lookup function that only three unit tests ever passed — a test-only seam in production code. Those tests asserted the wrapper's own try/catch branches through the fake, i.e. they restated the implementation (audit: test-only production code, test-only.md finding 5).

The fix

+2/−48: the lookup type and option are deleted, findActiveDaemonSessionSummary is called directly, the three fake-lookup tests and their import are gone, and the function's now-unimported export keyword is dropped. The real fallbackOnError policy and its production caller are byte-identical.

How it's verified

Reviewer confirmed no other caller passed the option, the deleted tests covered no user-relevant obligation, and the remaining 52 routing tests pass. tsgo/biome clean; full CI-style suite failure set identical to stack base (two unrelated full-load flakes pass focused on both branches). Two-model implement/review loop, approved first pass.

Stacked on #1737 (test the whole stack at the leaf; merge base-first).

Note: intentionally no Linear ticket for this cleanup stack, so that check stays red.

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Note

Low Risk
Internal refactor with no change to production lookup or error-fallback policy; only breaks out-of-tree imports of the formerly exported wrapper.

Overview
Removes the test-only injection point for interactive startup daemon active-session lookup: the optional lookup callback and its type alias are deleted, and findActiveDaemonSessionSummaryForInteractiveStartup always calls findActiveDaemonSessionSummary directly.

The wrapper is now internal (no longer exported). fallbackOnError behavior and the production caller that passes { fallbackOnError: !publicCommand.attachAgent } are unchanged.

Three unit tests that stubbed lookup to exercise the wrapper’s try/catch are removed; remaining routing tests still cover the exported decision helpers.

^{Reviewed by Cursor Bugbot for commit e290652. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Remove test-only daemon-lookup override seam from main.ts

Removes the ActiveDaemonSessionSummaryLookup type alias and the optional lookup property from ActiveDaemonSessionSummaryLookupOptions in main.ts. The function findActiveDaemonSessionSummaryForInteractiveStartup is no longer exported and always calls findActiveDaemonSessionSummary directly. Deletes three tests in main-interactive-routing.test.ts that depended on injecting a custom lookup.

• Risk: findActiveDaemonSessionSummaryForInteractiveStartup is now internal; any out-of-tree importers will break. The lookup option is silently ignored if still passed.

^{Macroscope summarized e290652.}

Linear ticket: ENG-5658
(ticket linked above)

[snimu]

Superseded by #1824: GitHub's stack lock prevents retargeting stacked PRs, so this PR was recreated as a plain PR against main (same branch, same content, all review threads here are resolved). Please review/merge #1824 instead.