emrg: gui — fix TUI composer height for multiline input misalignment

Agent.md

@@ -119,7 +119,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.token; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (1146) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (1147) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (95: 45 daemon_client + 20 conn-manager + 8 integration + 6 build-config + 7 gui-state + 3 preload-api + 4 boot-contract + 2 theme-guard) — syntax: `node --check main.js preload.js daemon_client.js`
 Renderer: `cd emrg/gui/renderer && npm run typecheck && npm test` (476: 5 snapshot-store + 9 utils + 3 ErrorBoundary + 2 App smoke + 11 commands + 4 copywriting + 11 i18n + 11 markdown + 16 transcript + 10 TranscriptView + 15 history + 22 composer + 31 Composer + 6 LinkDialog + 12 sidebar + 17 Sidebar + 9 fileTree + 9 FileTree + 16 resultPanel + 8 ResultPanel + 27 workspaceView + 10 WorkspaceView + 10 dialog + 6 Dialog + 9 ConfirmDialog + 9 RenameDialog + 10 dialogLists + 3 HelpDialog + 9 MemoryDialog + 6 SkillsDialog + 9 openSession + 6 WelcomeDialog + 8 OpenSessionDialog + 7 NewSessionDialog + 7 rewind + 8 RewindDialog + 7 GithubDeviceDialog + 15 daemonBridge + 7 DaemonBridgeProvider + 26 Shell + 15 DialogHost + 20 SettingsPanel + 6 TaskFormDialog + 5 RantDialog + 4 vendorMarkdown) + `npm run build` → `renderer/dist/`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)

emrg/client/python_tui/terminal.py

@@ -249,6 +249,17 @@ def _get_lines(name: str) -> list[object]:
         status_lines = _get_lines("status")[:1]
         composer_lines = _get_lines("composer")[:10]
         prompt_lines = _get_lines("prompts")[:1]
+        # rant 2026-08-28T22:53:24 — composer height must track the composer's
+        # actual rendered line count, not a hard-coded 3.  A multiline input
+        # (text containing "\n", e.g. pasted text or pressing Enter first)
+        # renders more lines than single-line input; a fixed height makes the
+        # viewport's region model (composer_height / chat_height / chat_region)
+        # disagree with what write_lines_to_buffer actually lays out, which is
+        # the reported "错行" (input content misaligned with the "> " prompt).
+        # Here we sync the model with reality so every downstream consumer uses
+        # the correct height.  The render loop already computes allocation from
+        # len(composer_lines) below; this keeps the viewport object in lockstep.
+        self.viewport.composer_height = len(composer_lines)
         # Get ALL chat lines first (without truncation) so we know the real
         # needed height.  Truncation depends on viewport_height, but
         # viewport_height should depend on content — not the other way around.

tests/test_terminal_render.py

@@ -94,3 +94,52 @@ def test_shutdown_clears_screen():
     # 清屏后归位 (0,0)：CLEAR_SCREEN 之后必须紧跟 CURSOR_HOME
     from emrg.client.python_tui.output import CURSOR_HOME
     assert out.index(CLEAR_SCREEN) < out.index(CURSOR_HOME), "clear screen must precede cursor home"
+
+
+class FakeComposer:
+    """Composer fake that mimics InputWidget.render: one top/bottom separator line
+    plus one Line per logical input line (multi-line text → more than 3 rows).
+
+    rant 2026-08-28T22:53:24 — a fixed composer_height=3 mis-models multiline
+    input; the viewport must track the actual rendered row count.
+    """
+
+    def __init__(self, text: str) -> None:
+        self.text = text
+        self.dirty = True
+
+    def render(self, ctx: RenderContext) -> list[Line]:
+        lines = [Line(spans=[Span(text="─" * ctx.width)])]
+        # Split on "\n": each logical line, including leading/trailing empty
+        # strings (matches InputWidget.render's raw = text.split("\n")).
+        for logical in self.text.split("\n"):
+            lines.append(Line(spans=[Span(text="> " + logical)]))
+        lines.append(Line(spans=[Span(text="─" * ctx.width)]))
+        return lines
+
+
+def test_composer_height_tracks_multiline_render():
+    """viewport.composer_height must reflect the composer's actual line count.
+
+    For a single-line input the composer renders 3 rows (sep + content + sep).
+    For multiline input (text containing "\n") it renders more. A hard-coded
+    height of 3 would make the viewport's region model disagree with the real
+    layout → the reported "错行" (composer content misaligned with "> ").
+    """
+    term = Terminal()
+    term.mount(composer=FakeComposer("hello"))
+    with redirect_stdout(io.StringIO()):
+        term.render(full=True)
+    assert term.viewport.composer_height == 3, "single-line → 3 rows (sep+content+sep)"
+
+    term2 = Terminal()
+    term2.mount(composer=FakeComposer("line1\nline2"))
+    with redirect_stdout(io.StringIO()):
+        term2.render(full=True)
+    assert term2.viewport.composer_height == 4, "2 logical lines → 4 rows"
+
+    term3 = Terminal()
+    term3.mount(composer=FakeComposer("\ntest"))
+    with redirect_stdout(io.StringIO()):
+        term3.render(full=True)
+    assert term3.viewport.composer_height == 4, "leading newline → 4 rows"