feat(api): 访谈人格/回复长度策略、口述归一、背景语气与输入净稿全链路

Chat 访谈
- 新增 persona 系统（default / warm_listener / curious_guide）与 background_voice 语气层
- 回复长度由 compute_reply_plan 统一决策（brief / standard / expanded），融合信息密度启发式
- 输入净稿（input_normalize）：编排层可选 rules/llm 归一用户口语后再喂模型与记忆检索
- 记忆证据注入：按用户话检索 memory evidence 并注入 prompt

Memoir 回忆录
- 口述归一（oral_normalize）：segment 原文保留，story 管线取派生净稿作叙事输入
- segment 入队批次门闸：累计字数 + 最长等待秒数，减少零碎提交
- fidelity_check / prompts / narrative_agent 微调
- Alembic 0005：清理跨章节 story 外键

Infra
- Dockerfile 加入 ffmpeg
- pyproject.toml 新增依赖并同步 uv.lock
- .env.example / .env.production 补全新配置项

Tests
- 新增 test_background_voice、test_chat_input_normalize、test_experience_regressions
- 扩展 test_interview_prompts、test_interview_reply_length、test_story_route_oral_invariant

Made-with: Cursor

api/tests/test_background_runner.py

@@ -0,0 +1,165 @@
+"""BackgroundTaskRunner：字数门闸、超时、flush（纯函数 + 异步 mock）。"""
+
+from __future__ import annotations
+
+import asyncio
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from app.features.memoir import background_runner as br
+
+
+def test_batch_ready_for_submit_min_chars_zero() -> None:
+    assert br._batch_ready_for_submit(
+        min_chars=0,
+        max_wait_seconds=60.0,
+        total_text_chars=0,
+        elapsed_seconds=0.0,
+    )
+
+
+def test_batch_ready_for_submit_chars_met() -> None:
+    assert br._batch_ready_for_submit(
+        min_chars=50,
+        max_wait_seconds=60.0,
+        total_text_chars=50,
+        elapsed_seconds=1.0,
+    )
+
+
+def test_batch_ready_for_submit_not_ready() -> None:
+    assert not br._batch_ready_for_submit(
+        min_chars=50,
+        max_wait_seconds=60.0,
+        total_text_chars=10,
+        elapsed_seconds=5.0,
+    )
+
+
+def test_batch_ready_for_submit_max_wait_elapsed() -> None:
+    assert br._batch_ready_for_submit(
+        min_chars=50,
+        max_wait_seconds=60.0,
+        total_text_chars=10,
+        elapsed_seconds=60.0,
+    )
+
+
+def test_next_retry_sleep_seconds() -> None:
+    assert br._next_retry_sleep_seconds(5.0, 60.0, 1.0) == 5.0
+    assert br._next_retry_sleep_seconds(5.0, 60.0, 58.0) == 2.0
+    assert br._next_retry_sleep_seconds(5.0, 60.0, 60.0) == 0.0
+
+
+@pytest.mark.asyncio
+async def test_flush_pending_submits_without_gate(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_min_chars", 9999)
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_max_wait_seconds", 9999.0)
+
+    submitted: list[tuple[str, list[str]]] = []
+
+    async def fake_submit(uid: str, ids: list[str]) -> str:
+        submitted.append((uid, ids))
+        return "tid"
+
+    runner = br.BackgroundTaskRunner(debounce_seconds=30)
+    uid = "u1"
+    runner._batch[uid] = br._MemoirBatchState(
+        segment_ids=["s1", "s2"],
+        total_text_chars=3,
+        first_queued_monotonic=0.0,
+    )
+
+    with patch.object(runner, "_submit_task", new=AsyncMock(side_effect=fake_submit)):
+        await runner.flush_pending(uid)
+
+    assert submitted == [("u1", ["s1", "s2"])]
+    assert uid not in runner._batch
+
+
+@pytest.mark.asyncio
+async def test_queue_message_min_chars_zero_submits_after_debounce(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_min_chars", 0)
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_max_wait_seconds", 60.0)
+
+    submitted: list[tuple[str, list[str]]] = []
+
+    async def fake_submit(uid: str, ids: list[str]) -> str:
+        submitted.append((uid, ids))
+        return "tid"
+
+    runner = br.BackgroundTaskRunner(debounce_seconds=0)
+    with patch.object(runner, "_submit_task", new=AsyncMock(side_effect=fake_submit)):
+        await runner.queue_message("u1", "seg-a", text_char_count=0)
+        await asyncio.sleep(0.05)
+
+    assert submitted and submitted[0][1] == ["seg-a"]
+
+
+@pytest.mark.asyncio
+async def test_queue_message_not_ready_then_max_wait_submits(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_min_chars", 100)
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_max_wait_seconds", 0.12)
+
+    submitted: list[tuple[str, list[str]]] = []
+
+    async def fake_submit(uid: str, ids: list[str]) -> str:
+        submitted.append((uid, ids))
+        return "tid"
+
+    # debounce 须 >0，否则 retry sleep 为 0 会误走「立即提交」分支
+    runner = br.BackgroundTaskRunner(debounce_seconds=0.02)
+    with patch.object(runner, "_submit_task", new=AsyncMock(side_effect=fake_submit)):
+        await runner.queue_message("u1", "seg-a", text_char_count=5)
+        await asyncio.sleep(0.2)
+
+    assert submitted and submitted[0][1] == ["seg-a"]
+
+
+@pytest.mark.asyncio
+async def test_queue_message_not_ready_before_debounce_no_submit(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_min_chars", 100)
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_max_wait_seconds", 60.0)
+
+    submitted: list[tuple[str, list[str]]] = []
+
+    async def fake_submit(uid: str, ids: list[str]) -> str:
+        submitted.append((uid, ids))
+        return "tid"
+
+    runner = br.BackgroundTaskRunner(debounce_seconds=0.5)
+    with patch.object(runner, "_submit_task", new=AsyncMock(side_effect=fake_submit)):
+        await runner.queue_message("u1", "seg-a", text_char_count=5)
+        await asyncio.sleep(0.05)
+
+    assert submitted == []
+
+
+@pytest.mark.asyncio
+async def test_queue_message_chars_met_submits_after_debounce(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_min_chars", 10)
+    monkeypatch.setattr(br.settings, "memoir_segment_batch_max_wait_seconds", 60.0)
+
+    submitted: list[tuple[str, list[str]]] = []
+
+    async def fake_submit(uid: str, ids: list[str]) -> str:
+        submitted.append((uid, ids))
+        return "tid"
+
+    runner = br.BackgroundTaskRunner(debounce_seconds=0)
+    with patch.object(runner, "_submit_task", new=AsyncMock(side_effect=fake_submit)):
+        await runner.queue_message("u1", "seg-long", text_char_count=50)
+        await asyncio.sleep(0.05)
+
+    assert submitted and submitted[0][1] == ["seg-long"]