fix: audit fixes for async insight jobs + persist generation params

- Fix query param mismatch: rename GenerationStatusQuery.file_path to
  path so the client's app-resume buildQuery({ path: ... }) resolves
  correctly instead of always getting 400
- Remove dead _lib_id bindings from both generate handlers
- Return 202 Accepted instead of 200 from generate endpoints
- Restore OpenTelemetry span instrumentation on generate handlers
- Remove stale UNIQUE constraint from initial migration (incompatible
  with plain-INSERT DAO)
- Add tests for status guard: complete_job/fail_job are no-ops when
  job is already cancelled, and cancel_job by id
- Persist generation params (num_ctx, temperature, top_p, top_k, min_p,
  system_prompt, persona_id) on the photo_insights table for auditing

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/main.rs

@@ -75,6 +75,22 @@ fn main() -> std::io::Result<()> {
 
     run_migrations(&mut connect()).expect("Failed to run migrations");
 
+    // Recover orphaned insight generation jobs from a previous crash.
+    {
+        use crate::database::{InsightGenerationJobDao, SqliteInsightGenerationJobDao};
+        let mut dao = SqliteInsightGenerationJobDao::new();
+        let ctx = opentelemetry::Context::new();
+        match dao.recover_orphaned_jobs(&ctx) {
+            Ok(n) if n > 0 => {
+                info!("Recovered {} orphaned insight generation jobs", n);
+            }
+            Ok(_) => {}
+            Err(e) => {
+                log::warn!("Failed to recover orphaned insight jobs: {:?}", e);
+            }
+        }
+    }
+
     // One-shot retirement of the pre-content-hash HLS layout. Idempotent
     // — a second boot finds nothing and reports zero deletions, so it's
     // safe to leave wired in until the module is removed in a later
@@ -309,6 +325,7 @@ fn main() -> std::io::Result<()> {
                 .service(ai::generate_insight_handler)
                 .service(ai::generate_agentic_insight_handler)
                 .service(ai::generation_status_handler)
+                .service(ai::cancel_generation_handler)
                 .service(ai::get_insight_handler)
                 .service(ai::delete_insight_handler)
                 .service(ai::get_all_insights_handler)