[Bug]: Multiple memory leaks in vec0 operations (INSERT, DELETE, error paths)

[murillodutt]

Description

PR #258 identifies 7 memory leaks in sqlite-vec.c that have not been merged. These leaks occur in INSERT operations, DELETE operations, and error handling paths within vec0 virtual tables.

Since PR #258 has been open without review, I'm filing this as a bug to increase visibility.

Identified Leaks (from PR #258)

The leaks are in various code paths in sqlite-vec.c:

1. INSERT path — allocated buffers not freed on early return/error
2. DELETE path — chunk data not freed after processing
3. Error handling — several error branches skip cleanup of allocated memory
4. Query result construction — intermediate buffers leaked in edge cases

Impact

• Long-running applications that perform many INSERT/DELETE/query operations will see growing memory usage
• Production systems with high-throughput vector operations (e.g., embedding pipelines processing thousands of documents) are most affected
• Memory is not reclaimed until the database connection is closed

Environment

• sqlite-vec: 0.1.7-alpha.2 and 0.1.7-alpha.10 (PR Memory Leak Fixes #258 not merged in either)
• Observed on: macOS ARM64, Linux x64

Reference

PR #258 contains the specific fixes for all 7 leak sites.

Reported by Murillo Dutt