Port recent Warp terminal and UI improvements

Improve tab-group search, rename focus, history navigation, shell prompt and
completion handling, emoji width promotion, and macOS clipboard support.
Guard unavailable settings/model-selector/undo-close views and forward the
MCP OAuth callback issuer through the existing authentication flow.

Adapt local changes from 14 upstream Warp commits through f571865ca3f2,
reviewed from the latest 200 commits. Preserve Galaxy provider lifecycle,
permissions, storage, and branding; exclude hosted/cloud infrastructure.

Fix existing boolean-assertion lints and use stronger optimization with four
code-generation units for the app test target to fit macOS unwind offsets.
Production and dependency compilation settings remain unchanged.

Validation: two clean builds and a final build; both prescribed Clippy
commands with -D warnings; formatting, shell syntax and completion cleanup;
167 focused regression tests. Galaxy was not launched.

app/assets/bundled/bootstrap/zsh_body.sh

@@ -1390,6 +1390,7 @@ esac
 
   # The main logic for generating completions.
   function warp_main_completer () {
+    (( ${+functions[_generic]} )) || return 0
     # We want all the results listed.
     compstate[list_max]=-1
 
@@ -1422,12 +1423,17 @@ esac
     # Start by reading in the completion buffer.
     zle warp_read_completion_buffer
 
-    compprefuncs=( warp_mark_start_of_completions_for_compadd_override )
-    comppostfuncs=( warp_mark_end_of_completions )
-    COMPADD_OVERRIDE=true
-    zle warp_complete_via_compadd_override_internal
-    BUFFER=""
-    unset COMPADD_OVERRIDE
+    # Own the response frame even when compinit is missing or completion fails.
+    warp_mark_start_of_completions_for_compadd_override
+    {
+      local -a compprefuncs=() comppostfuncs=()
+      COMPADD_OVERRIDE=true
+      zle warp_complete_via_compadd_override_internal
+    } always {
+      unset COMPADD_OVERRIDE
+      warp_mark_end_of_completions
+      BUFFER=""
+    }
   }
 
   function warp_read_completion_buffer() {