Closes #55619

Summary

• Route buffer_search::UseSelectionForFind through BufferSearchBar::deploy instead of updating the query editor directly.
• Add an explicit seed-query override to deploy, so the Cmd-E action can force SeedQuerySetting::Always while regular deploy callers continue to pass None and respect the user’s seed_search_query_from_cursor setting.
• By going through deploy, Cmd-E now also runs the search path that keeps buffer-search navigation state in sync:
  • shows/initializes the search bar for the active searchable item
  • applies the seeded query via search_suggested
  • calls search, which updates the query editor, search options, active search query, search history, and macOS find pasteboard
  • refreshes searchable_items_with_matches and active_match_index
  • activates the current match after the search completes
• This ensures the subsequent Cmd-G action has the expected active query, match list, search token, and active match index to select the next result.
• Add a macOS-only end-to-end regression test using the default macOS keymap with simulate_keystrokes("cmd-e") and simulate_keystrokes("cmd-g").

Validation

• cargo test -p search test_cmd_e_then_cmd_g_uses_selection_for_find
• cargo fmt --check --package search --package zed_actions
• ./script/check-keymaps
• cargo check -p search
• cargo check -p workspace
• cargo check -p vim

Release Notes:

• Fixed macOS Cmd-E/Cmd-G find behavior so Cmd-E seeds find from the cursor or selection and Cmd-G advances through the newly seeded matches.