Add Google Takeout data import infrastructure

Implements Phase 1 & 2 of Google Takeout RAG integration:
- Database migrations for calendar_events, location_history, search_history
- DAO implementations with hybrid time + semantic search
- Parsers for .ics, JSON, and HTML Google Takeout formats
- Import utilities with batch insert optimization

Features:
- CalendarEventDao: Hybrid time-range + semantic search for events
- LocationHistoryDao: GPS proximity with Haversine distance calculation
- SearchHistoryDao: Semantic-first search (queries are embedding-rich)
- Batch inserts for performance (1M+ records in minutes vs hours)
- OpenTelemetry tracing for all database operations

Import utilities:
- import_calendar: Parse .ics with optional embedding generation
- import_location_history: High-volume GPS data with batch inserts
- import_search_history: Always generates embeddings for semantic search

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Cargo.toml

@@ -13,7 +13,7 @@ lto = "thin"
 actix = "0.13.1"
 actix-web = "4"
 actix-rt = "2.6"
-tokio = { version = "1.42.0", features = ["default", "process", "sync"] }
+tokio = { version = "1.42.0", features = ["default", "process", "sync", "macros", "rt-multi-thread"] }
 actix-files = "0.6"
 actix-cors = "0.7"
 actix-multipart = "0.7.2"
@@ -52,3 +52,5 @@ exif = { package = "kamadak-exif", version = "0.6.1" }
 reqwest = { version = "0.12", features = ["json"] }
 urlencoding = "2.1"
 zerocopy = "0.8"
+ical = "0.11"
+scraper = "0.20"