Preserve preview harness, editor, email and task improvements

Snapshot current maintainer-preview application changes and regression fixtures for integration into lab. Excludes local runtime data, evaluation outputs and source backups. Focused Python regression selection: 140 passed; full suite not certified.

tests/test_chat_spinner_completion_js.py

@@ -0,0 +1,99 @@
+"""Exercise the stream-owned sidebar cleanup for terminal and detached paths."""
+import json
+import subprocess
+from pathlib import Path
+
+
+def test_sidebar_completion_clears_only_the_owning_finished_stream():
+    root = Path(__file__).resolve().parents[1]
+    source = (root / 'static/js/chat.js').read_text()
+    # The finalizer is a sibling of try, so its completion flag must be in
+    # the shared outer scope alongside abortCtrl, not the SSE parser block.
+    assert source.count('let _streamSawDone = false;') == 1
+    assert source.index('let _streamSawDone = false;') < source.index('let abortCtrl = null;')
+    start = source.index('      if (_ownsStreamState && _streamSawDone) {')
+    end = source.index('      const _finallyRegistered', start)
+    script = '''
+      const cleanup = new Function('_ownsStreamState', '_streamSawDone', 'abortCtrl',
+        'sessionModule', 'streamSessionId', BODY);
+      const results = [];
+      for (const [owner, done, reason] of [
+        [true,true,null], [true,false,'user-stop'], [true,false,'detach'],
+        [false,true,null], [false,false,'user-stop'], [true,false,null]
+      ]) {
+        const calls=[];
+        cleanup(owner,done,{_reason:reason},{
+          markStreamComplete: id=>calls.push('complete:'+id),
+          clearStreaming: id=>calls.push('clear:'+id),
+        },'chat');
+        results.push(calls);
+      }
+      console.log(JSON.stringify(results));
+    '''.replace('BODY', json.dumps(source[start:end]))
+    result = subprocess.run(['node', '--input-type=module', '-e', script],
+                            capture_output=True, text=True, check=True)
+    assert json.loads(result.stdout) == [['complete:chat'], ['clear:chat'], [], [], [], []]
+
+
+def test_tool_wait_indicator_cannot_reappear_after_completion_or_stop():
+    root = Path(__file__).resolve().parents[1]
+    source = (root / 'static/js/chat.js').read_text()
+    start = source.index('      let _toolPauseTimer = null;')
+    end = source.index('      // Document streaming state', start)
+    # The only scheduling call belongs to tool completion, not prose deltas.
+    assert source.count('_scheduleToolWaitSpinner();') == 1
+    tool_output = source.index("json.type === 'tool_output'", source.index("json.type === 'tool_start')"))
+    assert source.index('_scheduleToolWaitSpinner();') > tool_output
+    script = r'''
+      const results = [];
+      for (const mode of ['waiting', 'done', 'stopped', 'replaced', 'hidden', 'cancelled']) {
+        let callback, shown = 0;
+        const streamSessionId = 'chat';
+        const abortCtrl = {signal: {aborted: mode === 'stopped'}};
+        const _activeStreams = new Map([['chat', {abortCtrl: mode === 'replaced' ? {} : abortCtrl}]]);
+        const sessionModule = {getCurrentSessionId: () => mode === 'hidden' ? 'other' : 'chat'};
+        let _streamSawDone = false, _thinkingSpinnerEl = null, _cancelThinkingTimer;
+        const _showThinkingSpinner = () => shown++;
+        const _thinkingLabel = () => 'Thinking';
+        const setTimeout = fn => {callback = fn; return 1;};
+        const clearTimeout = () => {callback = null;};
+        BODY
+        _scheduleToolWaitSpinner();
+        if (mode === 'done') _streamSawDone = true;
+        if (mode === 'cancelled') _cancelThinkingTimer();
+        callback?.();
+        results.push(shown);
+      }
+      console.log(JSON.stringify(results));
+    '''.replace('BODY', source[start:end])
+    result = subprocess.run(['node', '--input-type=module', '-e', script],
+                            capture_output=True, text=True, check=True)
+    assert json.loads(result.stdout) == [1, 0, 0, 0, 0, 0]
+
+
+def test_done_exits_reader_without_waiting_for_connection_close():
+    source = (Path(__file__).resolve().parents[1] / 'static/js/chat.js').read_text()
+    start = source.index("            if (data === '[DONE]') {")
+    end = source.index('            try {\n              const json = JSON.parse(data);', start)
+    body = source[start:end]
+    script = r'''
+      let reads = 0, cancellations = 0, _streamSawDone = false;
+      const reader = {cancel: async () => {cancellations++;}};
+      const _cancelThinkingTimer = () => {}, _removeThinkingSpinner = () => {};
+      const _activeStreams = new Map(), _backgroundStreams = new Map();
+      const streamSessionId = 'test', document = {visibilityState: 'visible'};
+      const _closeOpenThinkingMarkup = () => {};
+      const _isBg = false, isThinking = false;
+      streamReadLoop:
+      while (true) {
+        reads++;
+        if (reads > 1) throw Error('Waited for EOF after DONE');
+        for (const data of ['[DONE]']) {
+          BODY
+        }
+      }
+      console.log(JSON.stringify({reads, cancellations, done: _streamSawDone}));
+    '''.replace('BODY', body)
+    result = subprocess.run(['node', '--input-type=module', '-e', script],
+                            capture_output=True, text=True, check=True)
+    assert json.loads(result.stdout) == {'reads': 1, 'cancellations': 1, 'done': True}