docs(14-04): complete long text chunking plan

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v1.4
 milestone_name: Zhihu Anti-Crawler
 status: executing
-stopped_at: Completed 14-05 integrate cache and configuration toggle
-last_updated: "2026-03-23T23:00:00.000Z"
-last_activity: 2026-03-23 — Phase 14 Plan 05 completed (cache integration and config toggle)
+stopped_at: Completed 14-04 long text chunking
+last_updated: "2026-03-23T15:30:00.000Z"
+last_activity: 2026-03-23 — Phase 14 Plan 04 completed (long text chunking)
 progress:
   total_phases: 15
   completed_phases: 11
   total_plans: 44
-  completed_plans: 42
+  completed_plans: 41
   percent: 34
 ---
 
@@ -26,11 +26,11 @@ See: .planning/PROJECT.md (updated 2026-03-21)
 ## Current Position
 
 Phase: Phase 14 - 鲁棒性与成本控制
-Plan: 05 (completed)
+Plan: 04 (completed)
 Status: In progress
-Last activity: 2026-03-23 — Phase 14 Plan 05 completed (cache integration and config toggle)
+Last activity: 2026-03-23 — Phase 14 Plan 04 completed (long text chunking)
 
-Progress: [███░░░░░░░░] 34% (Phase 14/15, 5/5 plans complete)
+Progress: [██░░░░░░░░░] 34% (Phase 14/15, 4/6 plans complete)
 
 ### Phase 14 Goal
 提高 LLM 语义分段的稳定性和成本效率，实现智能缓存和优雅降级
@@ -91,13 +91,16 @@ v1.6 Phase 13 decisions (from 13-CONTEXT.md):
 - [Phase 14]: JSON parse errors (JSONDecodeError, ValueError) are recoverable - retry 1 time
 - [Phase 14]: Pydantic validation errors (ValidationError) are non-recoverable - immediate fallback
 - [Phase 14]: Parse failures log LLM output fragment (first 500 chars) for diagnosis
+- [Phase 14 Plan 04]: 分块阈值 5000 字符 - 与 ASRCorrector 的 batch_size 一致
+- [Phase 14 Plan 04]: 按句子边界分割 - 使用标点符号（。！？\n）保持语义完整性
+- [Phase 14 Plan 04]: 索引修正 - start_index/end_index 相对于原文位置，通过 offset 累加
+- [Phase 14 Plan 04]: 单个分块失败降级 - 该分块使用规则分段，不影响其他分块
+- [Phase 14 Plan 04]: 分块方法 - _split_into_chunks(), _merge_segment_results(), _segment_single_chunk(), _segment_multiple_chunks(), _fallback_chunk()
 - [Phase 14 Plan 05]: 缓存集成到 UnifiedSegmentationStrategy - 可选的 cache 参数
 - [Phase 14 Plan 05]: 缓存检查逻辑 - 调用 LLM 前检查缓存，命中时直接返回
 - [Phase 14 Plan 05]: 缓存保存逻辑 - LLM 调用成功后保存结果到缓存
 - [Phase 14 Plan 05]: SRTProcessor 缓存支持 - enable_cache 参数控制缓存创建
 - [Phase 14 Plan 05]: 配置开关验证 - enable_semantic_segmentation 控制 LLM/规则分段
-- [Phase 14 Plan 05]: 分块处理实现 - 实现 _segment_single_chunk 和 _segment_multiple_chunks 方法
-- [Phase 14 Plan 05]: 分块阈值 5000 字符 - 与 ASRCorrector 保持一致
 
 ### Technical Context