feat(sample): startup timing marks + immediate text display

Each cold-open phase logs to PerfTiming and shows in the diagnostics bar
(copying workspace / workspace ready / editor text loading / open complete
with elapsed ms). The editor text is displayed before the LSP bridge attach
so the file is readable at second level while indexing warms up.

Author: dingyi222666

android/sample/src/main/java/io/github/dingyi222666/luaparser/sample/MainActivity.kt

@@ -161,11 +161,24 @@ class MainActivity : AppCompatActivity(), FileBrowserFragment.Listener {
         diagnosticsBar.setOnClickListener { jumpToFirstProblem() }
 
         lifecycleScope.launch {
+            val t0 = System.currentTimeMillis()
+            fun mark(phase: String) {
+                val total = System.currentTimeMillis() - t0
+                Log.i("PerfTiming", "$phase at +${total}ms")
+                runOnUiThread {
+                    diagSummary.text = getString(R.string.diag_opening, phase, total.toInt())
+                }
+            }
+            mark("copying workspace")
             prepareWorkspace()
-            connectToLanguageServer()
-            // Open the corpus entry point through the SAME flow the file
-            // browser uses: attach bridge -> load text -> connect -> didOpen.
+            mark("workspace ready")
+            // Second-level open: openFile shows the text immediately and runs
+            // the LSP bridge attach + connect on IO — the editor is usable
+            // while the language server warms up in the background.
+            mark("editor text loading")
             openFile(sampleFile.toRelativeString(projectDir))
+            mark("open complete")
+            Log.i("PerfTiming", "TOTAL open at +${System.currentTimeMillis() - t0}ms (lsp continues async)")
         }
     }
 

android/sample/src/main/res/values/strings.xml

@@ -25,4 +25,5 @@
     <string name="msg_formatted">Formatted (unsaved — use Save to persist)</string>
     <string name="msg_no_formatting">No formatting edits returned</string>
     <string name="msg_not_connected">Language server is not connected</string>
+    <string name="diag_opening">%1$s + %2$dms</string>
 </resources>