# Phase 1 Enhancement Plan

**Source**: User request (2026-04-23)  
**Scope**: Frontend navigation + RAG Database management page + page-aware chunking with chunk PDFs  
**Status**: 🔄 In Progress — Feature 1 ✅ Complete, Feature 2 backend ✅ Complete, Feature 2 frontend & Feature 3 pending

---

## Objective

Enhance the existing Phase 1 application with three features:

1. **Navigation Bar** — Top nav bar with two pages: "LTT" (current query page) and "RAG Database"
2. **RAG Database Page** — View/manage ChromaDB documents (list, delete, upload)
3. **Page-Aware Chunking** — Chunks tagged with page numbers, saved as PDFs in `document_chunk/`, with clickable links in RAG responses

---

## Current State (Pre-Enhancement)

### Current State (Pre-Enhancement)

### What Exists
- Multi-page React app with react-router-dom routing
- Nav bar with "LTT" and "RAG Database" tabs
- "LTT" page at `/` with current query interface
- "RAG Database" placeholder page at `/rag-database`
- 2 API endpoints: `POST /api/v1/ingest`, `POST /api/v1/query`
- Flat chunking: PDF text extracted page-by-page but concatenated into one string before chunking
- Metadata per chunk: `filename`, `upload_date`, `content_summary`, `chunk_index`
- ChromaDB collection `documents` with UUID-based IDs (`{document_id}_{chunk_index}`)
- Frontend: pages in `pages/`, components in `components/`, TanStack Query, react-markdown

### What's Missing (Gaps This Plan Fills)
- ~~No routing or multi-page support~~ ✅ Done in Feature 1
- ~~No way to view what's stored in ChromaDB~~ ✅ Backend CRUD done (sub-phase 1.5.2)
- ~~No way to delete documents or chunks~~ ✅ Backend CRUD done (sub-phase 1.5.2)
- No page-level awareness in chunking (all pages flattened before token splitting)
- No persistent chunk files (chunks only exist as ChromaDB document text)
- No clickable links in RAG responses to view source chunks
- ~~Upload only via IngestPanel on the main query page~~ (IngestPanel stays on LTT, upload also coming to RAG DB page)

---

## Feature 1: Navigation Bar & Multi-Page Layout ✅ COMPLETE

**Completed**: 2026-04-23

### 1.1 Changes Required

**Frontend**:
- ~~Install `react-router-dom`~~ ✅
- ~~Create `frontend/src/components/NavBar.tsx` — top navigation bar~~ ✅
- ~~Create `frontend/src/pages/LTTPage.tsx` — move current App.tsx content here~~ ✅
- ~~Create `frontend/src/pages/RAGDatabasePage.tsx` — placeholder, fleshed out in Feature 2~~ ✅
- ~~Refactor `frontend/src/App.tsx` — Router + NavBar + route definitions~~ ✅

**Backend**: None

### 1.2 Nav Bar Design

```
┌─────────────────────────────────────────────────┐
│  🔍 LTT (active)  │  📚 RAG Database           │  ← top nav bar (fixed)
├─────────────────────────────────────────────────┤
│                                                  │
│  [Page content: LTT or RAG Database]             │
│                                                  │
└─────────────────────────────────────────────────┘
```

- Fixed top bar, full width
- Two tabs: "LTT" (current query page) and "RAG Database"
- Active tab highlighted
- "LTT" route: `/` (default)
- "RAG Database" route: `/rag-database`

### 1.3 Implementation Tasks

| Task | Description | Files | Status |
|------|-------------|-------|--------|
| Install react-router-dom | `npm install react-router-dom` | `package.json` | ✅ |
| Create NavBar component | Horizontal nav with two links | `frontend/src/components/NavBar.tsx` | ✅ |
| Create LTTPage | Extract current AppContent into page component | `frontend/src/pages/LTTPage.tsx` | ✅ |
| Create RAGDatabasePage | Placeholder page (scaffold for Feature 2) | `frontend/src/pages/RAGDatabasePage.tsx` | ✅ |
| Refactor App.tsx | BrowserRouter + Routes + NavBar wrapper | `frontend/src/App.tsx` | ✅ |

### 1.4 Acceptance Criteria

- [x] Nav bar visible at top of every page
- [x] Clicking "LTT" navigates to `/` and shows current query interface
- [x] Clicking "RAG Database" navigates to `/rag-database`
- [x] Current page highlighted in nav bar
- [x] All existing functionality preserved (query, ingest, response display)
- [x] Build passes, no TypeScript errors
- [x] 62/62 frontend tests pass

---

## Feature 2: RAG Database Management Page

### 2.1 Overview

A dedicated page to view and manage all documents/chunks stored in ChromaDB.

### 2.2 Backend Changes

**New API Endpoints**:

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/api/v1/documents` | List all documents with chunk counts |
| `GET` | `/api/v1/documents/{document_id}/chunks` | List all chunks for a document |
| `DELETE` | `/api/v1/documents/{document_id}` | Delete all chunks for a document |
| `DELETE` | `/api/v1/chunks/{chunk_id}` | Delete a single chunk |

**New/Modified Files**:

| File | Change |
|------|--------|
| `backend/app/routers/documents.py` | **NEW** — CRUD endpoints for documents/chunks |
| `backend/app/services/rag.py` | Add `list_documents()`, `list_chunks()`, `delete_document()`, `delete_chunk()` methods |
| `backend/app/models/documents.py` | **NEW** — Pydantic schemas for document/chunk listing |
| `backend/app/main.py` | Register `documents` router |

**New Pydantic Schemas** (`models/documents.py`):

```python
class DocumentInfo(BaseModel):
    document_id: str
    filename: str
    chunk_count: int
    upload_date: str

class ChunkInfo(BaseModel):
    chunk_id: str
    chunk_index: int
    content_summary: str
    page_number: int | None = None       # Added by Feature 3
    chunk_file_path: str | None = None   # Added by Feature 3

class DocumentListResponse(BaseModel):
    documents: List[DocumentInfo]
    total_documents: int
    total_chunks: int

class DeleteResponse(BaseModel):
    deleted: bool
    message: str
```

**Implementation Notes for ChromaDB Operations**:

- `list_documents()`: ChromaDB has no native "group by document" — need to `collection.get(include=["metadatas"])`, then group by `filename` and extract `document_id` from chunk IDs (format: `{document_id}_{chunk_index}`)
- `delete_document()`: Use `collection.delete(where={"filename": "..."})` or collect all chunk IDs matching the document_id prefix and call `collection.delete(ids=[...])`
- `delete_chunk()`: Use `collection.delete(ids=[chunk_id])`
- **Important**: When deleting a document, also clean up associated chunk PDF files from `document_chunk/` (Feature 3)

### 2.3 Frontend Changes

**New/Modified Files**:

| File | Change |
|------|--------|
| `frontend/src/pages/RAGDatabasePage.tsx` | Full implementation |
| `frontend/src/components/DocumentList.tsx` | **NEW** — Document table/cards |
| `frontend/src/components/ChunkList.tsx` | **NEW** — Chunk table for selected document |
| `frontend/src/components/DocumentUpload.tsx` | **NEW** — Upload form (can reuse IngestPanel logic) |
| `frontend/src/lib/api.ts` | Add `listDocuments()`, `deleteDocument()`, `deleteChunk()` |
| `frontend/src/lib/queries.tsx` | Add TanStack Query hooks for new endpoints |
| `frontend/src/types/index.ts` | Add `DocumentInfo`, `ChunkInfo`, `DeleteResponse` types |

### 2.4 Page Layout

```
┌──────────────────────────────────────────────────┐
│  RAG Database                         [Upload]   │
├──────────────────────────────────────────────────┤
│  Total: 5 documents, 342 chunks                  │
│                                                   │
│  ┌──────────────────────────────────────────────┐ │
│  │ 📄 NEC4 ACC.pdf    │ 101 chunks │ 2026-04-23 │ │
│  │    [View Chunks]  [Delete]                    │ │
│  ├──────────────────────────────────────────────┤ │
│  │ 📄 meeting_notes.docx │ 45 chunks │ 2026-04-22│ │
│  │    [View Chunks]  [Delete]                    │ │
│  ├──────────────────────────────────────────────┤ │
│  │ 📄 budget_report.txt │ 28 chunks │ 2026-04-21│ │
│  │    [View Chunks]  [Delete]                    │ │
│  └──────────────────────────────────────────────┘ │
│                                                   │
│  [Expanded chunk view when "View Chunks" clicked] │
│  ┌──────────────────────────────────────────────┐ │
│  │ Chunk 0 │ p.3 │ "Discussion of budget..."     │ │
│  │          │ [View PDF]  [Delete Chunk]          │ │
│  ├──────────────────────────────────────────────┤ │
│  │ Chunk 1 │ p.4 │ "Allocation for Q4..."        │ │
│  │          │ [View PDF]  [Delete Chunk]          │ │
│  └──────────────────────────────────────────────┘ │
└──────────────────────────────────────────────────┘
```

### 2.5 Acceptance Criteria

- [x] `GET /api/v1/documents` returns all documents with chunk counts
- [x] `DELETE /api/v1/documents/{document_id}` removes all chunks from ChromaDB + associated chunk PDFs
- [x] `DELETE /api/v1/chunks/{chunk_id}` removes a single chunk
- [ ] RAG Database page shows all documents with chunk counts
- [ ] User can expand a document to see its chunks
- [ ] User can delete a document (with confirmation)
- [ ] User can delete individual chunks (with confirmation)
- [ ] User can upload documents from this page
- [ ] Stats displayed: total documents, total chunks
- [ ] Uploading a file with existing filename triggers automatic replacement (old data deleted first)

---

## Feature 3: Page-Aware Chunking & Chunk PDF Storage

### 3.1 Overview

When a document is uploaded:
1. Parse it page-by-page (PDF) or section-by-section (DOCX)
2. Each chunk is tagged with its source page number
3. Each chunk's source page is saved as a PDF in `document_chunk/`
4. RAG responses include clickable links to the chunk PDF

### 3.2 Backend Changes

#### 3.2.1 Page-Aware PDF Parsing

**Current**: `parse_pdf()` concatenates all pages into one string, losing page boundaries.

**New**: `parse_pdf_by_page()` returns `List[Tuple[int, str]]` — list of (page_number, page_text) tuples.

**Modified Files**:

| File | Change |
|------|--------|
| `backend/app/utils/pdf_parser.py` | Add `parse_pdf_by_page()` function |

```python
def parse_pdf_by_page(file_path: str) -> List[Tuple[int, str]]:
    """Parse PDF and return per-page text with page numbers (1-indexed)."""
    reader = PdfReader(file_path)
    pages = []
    for i, page in enumerate(reader.pages, start=1):
        text = page.extract_text()
        if text and text.strip():
            pages.append((i, text.strip()))
    return pages
```

**DOCX Note**: DOCX files don't have true page numbers. For DOCX, we can use paragraph-based indexing or skip page tracking. Suggested approach: chunk DOCX normally, set `page_number = None` in metadata.

#### 3.2.2 Page-Aware Chunking

**Current**: `TokenChunkingStrategy.chunk(text)` takes a flat string and splits by tokens.

**New**: Page-as-chunk-unit with overlap context from adjacent pages.

**Chunking Algorithm (confirmed)**:
```
For page N (1-indexed):
  overlap_before = last 200 tokens of page N-1 text (or empty if page 1)
  overlap_after  = first 200 tokens of page N+1 text (or empty if last page)
  chunk_text = overlap_before + page_N_text + overlap_after
```

- One chunk per page — **never split** a page even if it exceeds 1000 tokens
- Overlap provides surrounding context for better embedding/retrieval
- The `page_number` metadata always refers to the main page (N), not the overlap pages

**Modified Files**:

| File | Change |
|------|--------|
| `backend/app/utils/chunking.py` | Add `chunk_pages()` method to `TokenChunkingStrategy` |

```python
def chunk_pages(
    self, pages: List[Tuple[int, str]], overlap_tokens: int = 200
) -> List[Tuple[str, int]]:
    """Chunk page-segmented text with overlap from adjacent pages.

    For each page, creates one chunk containing:
      [last overlap_tokens of previous page] + [full current page] + [first overlap_tokens of next page]

    Args:
        pages: List of (page_number, page_text) tuples. 1-indexed.
        overlap_tokens: Number of tokens to include from adjacent pages.

    Returns:
        List of (chunk_text, page_number) tuples. One chunk per page.
    """
    if not pages:
        return []

    # Tokenize all pages upfront
    tokenized = []
    for page_num, page_text in pages:
        tokens = self._encoding.encode(page_text)
        tokenized.append((page_num, tokens, page_text))

    chunks = []
    for i, (page_num, tokens, _text) in enumerate(tokenized):
        parts = []

        # Overlap from previous page (last N tokens)
        if i > 0:
            prev_tokens = tokenized[i - 1][1]
            overlap = prev_tokens[-overlap_tokens:] if len(prev_tokens) >= overlap_tokens else prev_tokens
            if overlap:
                parts.append(self._encoding.decode(overlap))

        # Full current page text (use original text, not re-decoded)
        parts.append(pages[i][1])

        # Overlap from next page (first N tokens)
        if i < len(tokenized) - 1:
            next_tokens = tokenized[i + 1][1]
            overlap = next_tokens[:overlap_tokens] if len(next_tokens) >= overlap_tokens else next_tokens
            if overlap:
                parts.append(self._encoding.decode(overlap))

        chunk_text = "\n".join(parts)
        chunks.append((chunk_text, page_num))

    return chunks
```

#### 3.2.3 Chunk PDF Generation & Storage

**New directory**: `document_chunk/` (at project root, alongside `chroma_db/`)

**Naming convention**: `{original_filename_without_ext}_page_{page_number}.pdf`

Example: `NEC4 ACC_page_3.pdf`

**One file per page** — multiple chunks never exist for a page (decision: never split a page), so deduplication is not needed.

**Content**: The actual page extracted from the source PDF — preserves original formatting, layout, tables, images. Not a generated text PDF.

**Modified/New Files**:

| File | Change |
|------|--------|
| `backend/app/utils/pdf_extractor.py` | **NEW** — Extract and save individual PDF pages |
| `backend/app/core/config.py` | Add `DOCUMENT_CHUNK_PATH` setting (default: `./document_chunk`) |

```python
# pdf_extractor.py
from pypdf import PdfReader, PdfWriter

def extract_page_as_pdf(source_path: str, page_number: int, output_path: str) -> str:
    """Extract a single page from a PDF and save as a new PDF file.
    
    Args:
        source_path: Path to original PDF
        page_number: 1-indexed page number
        output_path: Where to save the extracted page PDF
    
    Returns:
        The output_path of the saved PDF
    """
    reader = PdfReader(source_path)
    writer = PdfWriter()
    writer.add_page(reader.pages[page_number - 1])  # 0-indexed in reader
    with open(output_path, "wb") as f:
        writer.write(f)
    return output_path
```

**Note**: For DOCX files, chunk PDF generation is skipped (set `chunk_file_path = None` in metadata). Only PDFs support page extraction.

#### 3.2.4 Enhanced Metadata

**Current metadata**:
```python
{
    "filename": "report.pdf",
    "upload_date": "2026-04-23T...",
    "content_summary": "First 200 chars...",
    "chunk_index": 0,
}
```

**Enhanced metadata**:
```python
{
    "filename": "report.pdf",
    "upload_date": "2026-04-23T...",
    "content_summary": "First 200 chars...",
    "chunk_index": 0,
    "page_number": 3,                              # NEW
    "chunk_file_path": "report_page_3.pdf",        # NEW (relative path)
    "document_id": "uuid-string",                   # NEW (for grouping)
}
```

**Modified Files**:

| File | Change |
|------|--------|
| `backend/app/utils/metadata.py` | Add `page_number`, `chunk_file_path`, `document_id` to metadata |
| `backend/app/models/common.py` | Add new fields to `SourceMetadata` |

#### 3.2.5 Chunk File Serving Endpoint

**New endpoint**:

| Method | Path | Description |
|--------|------|-------------|
| `GET` | `/api/v1/chunks/{file_path}/pdf` | Serve chunk PDF file |

**Modified Files**:

| File | Change |
|------|--------|
| `backend/app/routers/documents.py` | Add `GET /chunks/{file_path}/pdf` endpoint |

```python
@router.get("/chunks/{file_path}/pdf")
async def get_chunk_pdf(file_path: str):
    """Serve a chunk PDF file from document_chunk/ directory."""
    # Validate path to prevent directory traversal
    # Return FileResponse from DOCUMENT_CHUNK_PATH / file_path
```

#### 3.2.6 Ingestion Pipeline Refactor

The entire ingestion flow needs to be updated:

**Current flow**:
```
Upload → parse_pdf() → flat text → chunk() → metadata → store in ChromaDB
```

**New flow**:
```
Upload → check if filename exists → YES: delete old chunks + chunk PDFs (full replacement)
       → parse_pdf_by_page() → per-page text
       → chunk_pages() with 200-token overlap from adjacent pages
       → for each page: extract page as PDF → save to document_chunk/
       → enhanced metadata (page_number, chunk_file_path, document_id)
       → store in ChromaDB
```

**Same-filename replacement** (confirmed):
- On upload, query ChromaDB for existing chunks with matching `filename`
- If found: delete old chunk IDs from collection, delete old PDFs from `document_chunk/`
- Create new `document_id`, ingest fresh
- This ensures clean replacement without orphaned data

**Modified Files**:

| File | Change |
|------|--------|
| `backend/app/routers/ingest.py` | Refactor: page-aware parsing, chunk PDF generation, enhanced metadata, same-filename replacement |

### 3.3 Frontend Changes

**Modified Files**:

| File | Change |
|------|--------|
| `frontend/src/types/index.ts` | Add `page_number`, `chunk_file_path` to `SourceMetadata` |
| `frontend/src/components/ResponsePanel.tsx` | Render `chunk_file_path` as clickable link in sources |
| `frontend/src/components/ChunkList.tsx` | Show page number, link to chunk PDF |

**Source Card Update**:

Current source card shows: `filename`, `upload_date`, `content_summary`, `chunk_index`

Enhanced source card adds: `page_number` (e.g., "Page 3"), clickable "View Source" link opening chunk PDF

### 3.4 Directory Structure After Enhancement

```
legco_reranker/
├── app/
│   ├── backend/...
│   ├── frontend/...
│   └── chroma_db/                    # Existing
├── document_chunk/                    # NEW — chunk PDF files
│   ├── NEC4 ACC_page_1.pdf
│   ├── NEC4 ACC_page_2.pdf
│   ├── NEC4 ACC_page_3.pdf
│   └── meeting_notes_page_5.pdf
├── .plans/
└── ...
```

### 3.5 Acceptance Criteria

- [ ] PDF uploads produce page-aware chunks: 1 chunk per page with 200-token overlap from adjacent pages
- [ ] Each page is saved as a separate PDF (original page, not generated text) in `document_chunk/`
- [ ] Chunk PDF filename follows convention: `{filename}_page_{n}.pdf`
- [ ] Page numbers are sequential index (1, 2, 3...), not PDF internal labels
- [ ] Oversized pages are kept as single chunks (never split)
- [ ] `GET /api/v1/chunks/{file_path}/pdf` serves the original chunk PDF
- [ ] RAG response sources include `page_number` and `chunk_file_path`
- [ ] Frontend source cards show page number and clickable link
- [ ] Clicking source link opens/downloads the original chunk PDF
- [ ] DOCX uploads work without page numbers (graceful degradation, no chunk PDFs)
- [ ] Uploading a file with same filename replaces existing document (old chunks + PDFs deleted, new document_id)
- [ ] `document_chunk/` is `.gitignore`d
- [ ] Deleting a document also removes its chunk PDFs from `document_chunk/`

---

## Implementation Sequence

The three features have dependencies. Recommended order:

```
Feature 1 (Nav + Routing)     ← No backend changes, enables Feature 2
    │
    ▼
Feature 2 (RAG Database Page)  ← Needs Feature 1 for page routing
    │                            But backend CRUD endpoints are independent
    ▼
Feature 3 (Page-Aware Chunking) ← Modifies ingestion pipeline
                                 Enhances Feature 2 (chunk file links)
                                 Enhances ResponsePanel (clickable sources)
```

### Sub-Phase Breakdown

| Sub-Phase | Feature | Scope | Backend | Frontend | Status |
|-----------|---------|-------|---------|----------|--------|
| 1.5.1 | 1 | Nav bar + routing + page scaffold | None | NavBar, LTTPage, RAGDatabasePage, App.tsx refactor | ✅ Complete |
| 1.5.2 | 2 | Backend CRUD for documents/chunks | documents router, RAGService methods, schemas | None | ✅ Complete |
| 1.5.3 | 2 | Frontend RAG Database page | None | RAGDatabasePage, DocumentList, ChunkList, DocumentUpload, API hooks | 📋 Pending |
| 1.5.4 | 3 | Page-aware parsing & chunking | pdf_parser, chunking, metadata enhancements | None | 📋 Pending |
| 1.5.5 | 3 | Chunk PDF generation & storage | pdf_extractor, config, ingest pipeline refactor | None | 📋 Pending |
| 1.5.6 | 3 | Chunk file serving + frontend links | documents router endpoint | ResponsePanel clickable links, ChunkList updates | 📋 Pending |

### Parallelization Opportunities

- **1.5.1 and 1.5.2 can run in parallel** — Frontend routing changes and backend CRUD are independent
- **1.5.3 blocked by 1.5.1 + 1.5.2** — Needs both routing and backend endpoints
- **1.5.4 and 1.5.5 are sequential** — 1.5.5 depends on 1.5.4's page-aware parsing
- **1.5.6 blocked by 1.5.3 + 1.5.5** — Needs both frontend page and backend chunk serving

```
1.5.1 (Nav+Routing)  ─┐
                       ├─► 1.5.3 (RAG DB Page) ─┐
1.5.2 (Backend CRUD) ─┘                         │
                                                 ├─► 1.5.6 (Links)
1.5.4 (Page-Aware) ──► 1.5.5 (Chunk PDFs) ─────┘
```

---

## New Dependencies

### Backend
| Package | Purpose | Already installed? |
|---------|---------|--------------------|
| (none) | pypdf already supports page extraction | ✅ |

### Frontend
| Package | Purpose | Already installed? |
|---------|---------|--------------------|
| `react-router-dom` | Client-side routing | ✅ Installed |

---

## .gitignore Updates

```gitignore
# Chunk PDF storage
document_chunk/
```

---

## Risks & Mitigations

| Risk | Impact | Mitigation |
|------|--------|------------|
| ~~ChromaDB has no native "group by document" query~~ | ~~`list_documents()` needs manual grouping from all metadata~~ | ✅ Resolved: Groups by document_id extracted from chunk IDs via `rsplit("_", 1)` |
| Large PDFs → many chunk PDF files | Disk usage grows | One PDF per unique page (not per chunk). Pages shared by chunks reuse same file. |
| Chunk spans multiple pages | Ambiguous page assignment | Tag chunk with STARTING page only. Note in UI. |
| DOCX has no page numbers | `page_number` is None for DOCX chunks | Graceful degradation — show "N/A" or hide page info for DOCX. |
| Deleting documents must clean up chunk files | Orphan files if deletion fails | Delete files after successful ChromaDB deletion. Log failures for manual cleanup. |
| Path traversal in chunk PDF endpoint | Security risk | Validate `file_path` doesn't contain `..` or absolute paths. Use whitelist of known files. |
| ChromaDB 1.5.8 requires `name()` on embedding functions | `_EmbeddingFunctionWrapper` crashes on `collection.get()` | ✅ Fixed: Added `name()` method returning `"custom_embedding_wrapper"` |
| Existing ChromaDB data corrupted (HNSW segment error) | Endpoints return 500 against existing `chroma_db/` | Pre-existing issue. Works with fresh DB. May need `chroma_db` reset for production. |

---

## Decisions (Confirmed)

| # | Question | Decision |
|---|----------|----------|
| 1 | Chunk algorithm | **Page-as-chunk-unit**. Each chunk = `[last 200 tokens of prev page] + [full current page text] + [first 200 tokens of next page]`. One chunk per page — never split a page even if oversized. |
| 2 | DOCX chunk PDFs | **No**. Only PDFs get chunk PDFs. DOCX chunks show text preview only. |
| 3 | IngestPanel placement | **Keep on LTT page** + also add upload on RAG Database page. |
| 4 | Re-ingestion / same filename | **Full replacement**. Delete old chunks + old chunk PDFs + create new `document_id`. |
| 5 | Chunk PDF content | **Original page from source PDF**. Extract actual page — preserves formatting, tables, images. |
| 6 | Page numbering | **Sequential index** (1, 2, 3...). Not PDF internal labels. |
| 7 | Oversized pages | **Never split**. One chunk per page regardless of token count. |

## Open Questions

None — all resolved.

---

## Test Plan

### Backend Tests (New Files)

| File | Coverage |
|------|----------|
| `test_phase1_documents_router.py` | ✅ GET /documents, DELETE /documents/{id}, DELETE /chunks/{id} (8 tests, all pass) |
| `test_phase1_pdf_parser_pages.py` | parse_pdf_by_page() — multi-page PDFs, single-page, empty |
| `test_phase1_page_aware_chunking.py` | chunk_with_pages() — cross-page chunks, single-page chunks |
| `test_phase1_pdf_extractor.py` | extract_page_as_pdf() — valid page, out-of-range, corrupt PDF |
| `test_phase1_chunk_serving.py` | GET /chunks/{path}/pdf — valid file, missing file, path traversal |

### Frontend Tests (New Files)

| File | Coverage |
|------|----------|
| `NavBar.test.tsx` | Navigation links, active state |
| `RAGDatabasePage.test.tsx` | Document list, delete, upload |
| `DocumentList.test.tsx` | Document cards, expand/collapse |
| `ChunkList.test.tsx` | Chunk table, page numbers, PDF links |

### Acceptance Tests

| File | Coverage |
|------|----------|
| `test_acceptance_phase1_documents_crud.py` | Real ChromaDB CRUD with list, delete |
| `test_acceptance_phase1_page_chunking.py` | Real PDF upload → page-aware chunks → chunk PDFs exist |
| `test_acceptance_phase1_chunk_links.py` | Full flow: upload → query → response has clickable chunk links |