fix: staging CI review issues (batch 1) (#883)

* fix: address staging-ci-review issues (batch 1)

- #811: Fix unreachable error handling in worker — restructure .await?
  to explicit match on nested Result so token budget errors are properly
  logged and marked as failed
- #813: Combine metadata + token budget into single update_context()
  call to prevent concurrent worker observing partial state
- #814: Persist max_tokens and total_tokens_used to both PostgreSQL and
  libSQL backends — add V12 migration, update save_job/get_job
- #815: Cap user-supplied max_tokens at configured max_tokens_per_job
  to prevent budget bypass via metadata injection
- #869: Release locks before async I/O in webhook handler (http.rs) and
  SIGHUP handler (main.rs) to prevent blocking concurrent requests

Fixes: #811, #813, #814, #815, #869

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: address PR #883 review feedback

- Fix min(user_val, 0) bug: guard for unlimited config (max_tokens_per_job == 0)
- Remove duplicate columns from libSQL base SCHEMA (v12 migration is sole source)
- Use get_i64() helper for consistency in libsql/jobs.rs
- Add regression tests for scheduler token budget capping

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

src/db/libsql/jobs.rs

@@ -30,8 +30,9 @@ impl JobStore for LibSqlBackend {
                     id, conversation_id, title, description, category, status, source,
                     user_id,
                     budget_amount, budget_token, bid_amount, estimated_cost, estimated_time_secs,
-                    actual_cost, repair_attempts, created_at, started_at, completed_at
-                ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14, ?15, ?16, ?17, ?18)
+                    actual_cost, repair_attempts, max_tokens, total_tokens_used,
+                    created_at, started_at, completed_at
+                ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14, ?15, ?16, ?17, ?18, ?19, ?20)
                 ON CONFLICT (id) DO UPDATE SET
                     title = excluded.title,
                     description = excluded.description,
@@ -42,6 +43,8 @@ impl JobStore for LibSqlBackend {
                     estimated_time_secs = excluded.estimated_time_secs,
                     actual_cost = excluded.actual_cost,
                     repair_attempts = excluded.repair_attempts,
+                    max_tokens = excluded.max_tokens,
+                    total_tokens_used = excluded.total_tokens_used,
                     started_at = excluded.started_at,
                     completed_at = excluded.completed_at
                 "#,
@@ -61,6 +64,8 @@ impl JobStore for LibSqlBackend {
                     estimated_time_secs,
                     ctx.actual_cost.to_string(),
                     ctx.repair_attempts as i64,
+                    ctx.max_tokens as i64,
+                    ctx.total_tokens_used as i64,
                     fmt_ts(&ctx.created_at),
                     fmt_opt_ts(&ctx.started_at),
                     fmt_opt_ts(&ctx.completed_at),
@@ -78,7 +83,8 @@ impl JobStore for LibSqlBackend {
                 r#"
                 SELECT id, conversation_id, title, description, category, status, user_id,
                        budget_amount, budget_token, bid_amount, estimated_cost, estimated_time_secs,
-                       actual_cost, repair_attempts, created_at, started_at, completed_at
+                       actual_cost, repair_attempts, max_tokens, total_tokens_used,
+                       created_at, started_at, completed_at
                 FROM agent_jobs WHERE id = ?1
                 "#,
                 params![id.to_string()],
@@ -111,12 +117,12 @@ impl JobStore for LibSqlBackend {
                     estimated_duration: estimated_time_secs
                         .map(|s| std::time::Duration::from_secs(s as u64)),
                     actual_cost: get_decimal(&row, 12),
-                    total_tokens_used: 0,
-                    max_tokens: 0,
+                    max_tokens: get_i64(&row, 14) as u64,
+                    total_tokens_used: get_i64(&row, 15) as u64,
                     repair_attempts: get_i64(&row, 13) as u32,
-                    created_at: get_ts(&row, 14),
-                    started_at: get_opt_ts(&row, 15),
-                    completed_at: get_opt_ts(&row, 16),
+                    created_at: get_ts(&row, 16),
+                    started_at: get_opt_ts(&row, 17),
+                    completed_at: get_opt_ts(&row, 18),
                     transitions: Vec::new(),
                     metadata: serde_json::Value::Null,
                     extra_env: std::sync::Arc::new(std::collections::HashMap::new()),