docs: add phases, tasks, and chunking strategies documentation

Why:
- Need implementation plan and task tracking documentation
- Need strategy explanations for reference

Changes:
- phases.md: 5-phase implementation plan with status tracking
- tasks.md: 25 tasks mapped to phases and steps
- chunking_strategies.md: detailed explanations of all 5 strategies

docs/tasks.md

@@ -0,0 +1,56 @@
+# Tasks
+
+All tasks for the RAG Chunking Strategy Benchmarking Framework.
+Each task maps to a Phase and Step in [phases.md](phases.md).
+
+Status legend: `DONE` `IN_PROGRESS` `TODO`
+
+## Phase 1 — Document Parsing + Storage
+
+| # | Task | Status | Step |
+|---|------|--------|------|
+| 1 | Design FastAPI application architecture and project structure | DONE | — |
+| 2 | Implement DOCX document loading and processing pipeline | DONE | 3 |
+| 3 | Add configurable application settings and experiment parameters | DONE | 1 |
+| 4 | Implement Qdrant vector database integration and collection management | DONE | 2 |
+
+## Phase 2 — Chunking Strategies
+
+| # | Task | Status | Step |
+|---|------|--------|------|
+| 5 | Create chunking strategy interface and abstraction layer | TODO | 5 |
+| 6 | Implement Structure-Aware Markdown chunking strategy | TODO | 6 |
+| 7 | Implement Recursive chunking strategy | TODO | 6 |
+| 8 | Implement Semantic chunking strategy | TODO | 6 |
+| 9 | Implement Parent-Child chunking strategy | TODO | 6 |
+| 10 | Implement Contextual Structure-Aware chunking strategy | TODO | 6 |
+| 11 | Implement OpenAI embedding service using text-embedding-3-small | TODO | 7 |
+| 12 | Implement strategy-based document processing API | TODO | 8 |
+
+## Phase 3 — Query Pipeline
+
+| # | Task | Status | Step |
+|---|------|--------|------|
+| 13 | Implement question answering API with configurable chunking strategy selection | TODO | 9–10 |
+
+## Phase 4 — Benchmarking + Evaluation
+
+| # | Task | Status | Step |
+|---|------|--------|------|
+| 14 | Implement benchmarking pipeline for comparing chunking strategies | TODO | 12 |
+| 15 | Implement RAG evaluation pipeline using GPT-4o-mini | TODO | 11 |
+| 16 | Implement experiment tracking and result storage system | TODO | 12 |
+| 17 | Create question-answer evaluation dataset from insurance regulation document | TODO | 12 |
+| 18 | Implement HTML benchmark report generation system | TODO | 14 |
+| 19 | Design HTML report structure for experiment comparison and visualization | TODO | 14 |
+| 20 | Create background processing jobs for document ingestion and benchmarking | TODO | 12 |
+
+## Phase 5 — Wiring + Verification
+
+| # | Task | Status | Step |
+|---|------|--------|------|
+| 21 | Add logging, request tracking, and cost monitoring | TODO | 15 |
+| 22 | Create API documentation and Swagger examples | TODO | 15 |
+| 23 | Create automated tests for chunking strategies and RAG workflow | TODO | 16 |
+| 24 | Validate end-to-end benchmarking workflow with insurance regulation dataset | TODO | 16 |
+| 25 | Analyze and compare chunking strategy performance results | TODO | 16 |