feat: Phase 3 — web dashboard, testing, and CI/CD

- Remove multi-marketplace from Phase 3
- Add FastAPI web UI on port 8766 with basic auth
- Add 6 Jinja2 templates (dashboard, keywords, users, ads, stats)
- Add pytest test suite (45 tests, 49% coverage)
- Add GitHub Actions CI/CD workflow
- Update docker-compose.yml to expose web UI port
- Update Dockerfile to include tests

docs/phase-3/Phase.md

@@ -1,12 +1,12 @@
-# Phase 3 — Scalability & Advanced Features
+# Phase 3 — Web Dashboard & Testing
 
 ## Scope
 
-This phase introduces **structural improvements** that make the project maintainable, extensible, and testable. Currently, the entire system is a single async Python process with no tests and no CI/CD pipeline. After this phase:
+This phase introduces **observability and reliability** improvements. Currently, the entire system is a single async Python process with no tests, no CI/CD pipeline, and no way to monitor what's happening without SSH-ing into the server. After this phase:
 
+- A **Web Dashboard** provides real-time visibility into keywords, ads, users, and stats
 - Automated tests provide confidence for every change (≥80% coverage)
 - CI/CD pipeline runs on every push to validate code quality
-- Multi-marketplace architecture enables adding new sources without modifying core logic
 
 ## Architecture
 
@@ -21,18 +21,17 @@ This phase introduces **structural improvements** that make the project maintain
 │    │   │   ├── db.py         (asyncpg pool mgmt)      │
 │    │   │   ├── bot.py        (Telegram handlers)      │
 │    │   │   ├── notifier.py   (message sending)        │
-│    │   │   ├── scraper.py    (base scraper class)     │
-│    │   │   ├── scrapers/                                 │
-│    │   │   │   ├── __init__.py                          │
-│    │   │   │   ├── willhaben.py  (willhaben-specific)   │
-│    │   │   │   └── base.py       (abstract base class)  │
+│    │   │   ├── scraper.py    (willhaben scraper)      │
+│    │   │   ├── web.py        (FastAPI dashboard)      │
 │    │   │   ├── health.py     (healthcheck endpoint)   │
-│    │   │   └── migrate.py    (migration runner)       │
+│    │   │   ├── migrate.py    (migration runner)       │
+│    │   │   └── templates/    (Jinja2 HTML templates)  │
 │    │   ├── tests/                                       │
 │    │   │   ├── conftest.py                                │
 │    │   │   ├── test_scraper.py                            │
 │    │   │   ├── test_notifier.py                           │
-│    │   │   └── ...                                      │
+│    │   │   ├── test_filters.py                            │
+│    │   │   └── test_web.py                                │
 │    │   ├── Dockerfile                                   │
 │    │   └── requirements.txt                             │
 │    ├── .github/                                         │
@@ -42,17 +41,17 @@ This phase introduces **structural improvements** that make the project maintain
 │    └── docker-compose.yml                               │
 └──────────────────────────────────────────────────────┘
 
-Multi-marketplace abstraction:
+Web Dashboard (FastAPI, port 8766):
   
-  ScraperBase (abstract):
-    - async fetch_ads(keyword) → list[dict]
-    - async parse_response(html/json) → list[dict]
-    - normalize_ad(raw) → dict with standard keys
-    
-  WillhabenScraper(ScraperBase):
-    - implements willhaben-specific URL, headers, parsing
+  GET /             → Dashboard (keywords overview, stats summary)
+  GET /keywords     → Keywords list with status, filters, subscribers
+  GET /keywords/<id> → Keyword detail (recent ads, price history, scrape logs)
+  GET /users        → Users list with settings
+  GET /ads          → Recent ads with search/filter
+  GET /stats        → JSON stats (extends existing /stats endpoint)
   
-  Future: KleinAnzeigenScraper, MobileScraper, ...
+  Auth: Basic Auth via WEB_UI_USERNAME / WEB_UI_PASSWORD env vars
+  Templates: Jinja2 with inline CSS (zero external dependencies)
 
 CI/CD Pipeline (.github/workflows/ci.yml):
   
@@ -71,6 +70,8 @@ Tests Structure:
     - test_scraper_pagination() — verify pagination logic with mock responses
     - test_price_filters() — verify filter functions
     - test_notification_retry() — verify retry queue behavior
+    - test_mute_digest() — verify mute hours and digest buffering
+    - test_web_endpoints() — verify web UI routes
   
   Integration tests:
     - Test against real willhaben API (rate-limited, cached)
@@ -81,13 +82,17 @@ Tests Structure:
 
 | Task | File | Description |
 |------|------|-------------|
-| Multi-marketplace abstraction layer | [task-multi-marketplace.md](./task-multi-marketplace.md) | Refactor `scraper.py` into a base class + per-marketplace implementations. Introduces a standard ad schema and factory for registering new sources. |
+| Web Dashboard (FastAPI + Jinja2) | [task-web-ui.md](./task-web-ui.md) | Add a read-only web dashboard for monitoring keywords, ads, users, and stats. Runs on port 8766 with basic auth. |
 | Test suite with pytest (≥80% coverage) | [task-testing-pytest.md](./task-testing-pytest.md) | Add comprehensive unit tests covering scraper parsing, notification logic, price/postcode filters, retry queue, and scheduler flow. Configure coverage thresholds. |
 
 ## General Acceptance Criteria
 
+- [ ] Web Dashboard is accessible at `http://<host>:8766` with basic auth
+- [ ] Dashboard shows keywords with status, filters, subscribers, and last scrape time
+- [ ] Dashboard shows recent ads with price, location, and keyword
+- [ ] Dashboard shows users with mute/digest settings
+- [ ] Dashboard shows stats (ads indexed, notifications sent, queue status)
 - [ ] CI pipeline runs on every push to `main` and feature branches — fails if lint or coverage checks are not met
 - [ ] Code coverage is ≥80% across all source files in `worker/src/`
-- [ ] Multi-marketplace abstraction works — adding a new marketplace requires only creating one file under `scrapers/` with no changes to core logic
-- [ ] All existing functionality (willhaben scraping, notifications) continues to work after refactoring
-- [ ] The `/health` endpoint exposes test results or coverage stats (optional enhancement)
+- [ ] All existing functionality (willhaben scraping, Telegram notifications, health server) continues to work
+- [ ] Health server still works on port 8765 (no regression)