Keep typed query when opening a search result

[seungjuchoi]

Problem

Opening a search result with Enter (SearchIntent::Navigate) committed a new search scoped to the picked task's display ref before opening its detail. Closing the detail then left a single-task search view (effectively AVEN-123 as the query) instead of the result list the user was actually choosing from, so there was no natural way back to the other matches.

Change

• Commit the typed query as the search view and select the picked task within it. Closing the detail now returns to the full result list, with the picked task still selected. g [ back-navigation to the pre-search view is unchanged.
• If the picked result is missing from the committed results (possible when the input changed after the preview ran), fall back to open_detail_task, the existing exact-task path used for linked tasks.

Tests

• navigate_search_result_commits_typed_query drives the real flow (type query → settle preview → pick second result → Enter) and asserts the committed view is TaskProjectionOrigin::Search { query: "needle" } with both matches listed and the picked task selected.
• navigate_search_result_missing_from_results_opens_exact_task covers the fallback.

cargo test --lib passes (1767 tests; RUST_MIN_STACK raised to get past the pre-existing debug-build stack overflow in focused_detail_child_removes_and_undo_restores_relationship, which also aborts on a clean main checkout). cargo fmt --check and cargo clippy --all-targets are clean.