Simplify API: remove topics, rename session→offer

- Remove topic-based grouping and discovery
- Rename sessions to offers for clarity
- Simplify to just POST /offer, POST /answer, POST /poll
- Add version to health endpoint
- Update database schema (sessions→offers table)
- Reduce offer timeout to 1 minute
- Server version: 0.0.1

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

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

wrangler.toml

@@ -5,14 +5,14 @@ compatibility_date = "2024-01-01"
 # D1 Database binding
 [[d1_databases]]
 binding = "DB"
-database_name = "rondevu-sessions"
+database_name = "rondevu-offers"
 database_id = "b94e3f71-816d-455b-a89d-927fa49532d0"
 
 # Environment variables
 [vars]
-SESSION_TIMEOUT = "60000"  # 1 minute in milliseconds
+OFFER_TIMEOUT = "60000"  # 1 minute in milliseconds
 CORS_ORIGINS = "*"  # Comma-separated list of allowed origins
-VERSION = "unknown"  # Set to git commit hash before deploying
+VERSION = "0.0.1"  # Semantic version
 
 # Build configuration
 [build]