Add warnings about schema changes and remove ad-hoc index creation

- Remove ad-hoc index creation from database.go Initialize method
- Add clear comments to both database.go and schema.sql warning that
  ALL schema changes must be made in schema.sql only
- We do not support migrations, schema changes outside schema.sql are forbidden

internal/database/database.go

@@ -22,6 +22,9 @@ import (
 	_ "github.com/mattn/go-sqlite3" // CGO SQLite driver
 )
 
+// IMPORTANT: NO schema changes are to be made outside of schema.sql
+// We do NOT support migrations. All schema changes MUST be made in schema.sql only.
+//
 //go:embed schema.sql
 var dbSchema string
 
@@ -127,16 +130,6 @@ func (d *Database) Initialize() error {
 		d.logger.Warn("Failed to VACUUM database", "error", err)
 	}
 
-	// Create any missing indexes for existing databases
-	missingIndexes := []string{
-		"CREATE INDEX IF NOT EXISTS idx_live_routes_origin_asn ON live_routes(origin_asn)",
-	}
-	for _, idx := range missingIndexes {
-		if err := d.exec(idx); err != nil {
-			d.logger.Warn("Failed to create index", "index", idx, "error", err)
-		}
-	}
-
 	return nil
 }
 

internal/database/schema.sql

@@ -1,3 +1,7 @@
+-- IMPORTANT: This is the ONLY place where schema changes should be made.
+-- We do NOT support migrations. All schema changes MUST be in this file.
+-- DO NOT make schema changes anywhere else in the codebase.
+
 CREATE TABLE IF NOT EXISTS asns (
 	id TEXT PRIMARY KEY,
 	number INTEGER UNIQUE NOT NULL,