fix(TASK-046): engine polish + wizard bypass + ETXTBSY retry

- unify hook base-env assembly on hooks::base_envs_parts (drop the
  hand-copied hook_base_envs in function/agents.rs; graph executor and
  spawn-result hooks now share the single construction site, test-pinned)
- factor the duplicated job.started dispatch in jobs.rs handle_start
  into one fire_job_started helper
- COYOTE_LLM_ERROR now carries the immediate error (to_string()),
  matching COYOTE_TOOL_ERROR; test pins the new format
- remove all stale #[allow(dead_code)] markers in src/hooks.rs
- test infra: rename install_warn_collector -> install_log_collector,
  add poison-symmetric warn_snapshot/debug_snapshot helpers, hoist a
  shared EnvVarGuard (TestConfigDirGuard now builds on it), add a
  same-fire payload-uniqueness test, and give global_tools env
  overrides the same malformed-JSON debug diagnostic as global_hooks
- inspection-only flags (--info et al) bypass the first-run wizard:
  missing config + info_flag returns Config::default() without writing
  anything, in both the sandbox and interactive arms (tests included)
- bound the shim-relocation test's exec in an ETXTBSY retry (10x50ms)
- document the intended 'roles' reserved-name asymmetry at
  resolve_bundle_name's gate

src/config/agent.rs

@@ -1019,10 +1019,13 @@ impl AgentConfig {
         if let Some(v) = read_env_value::<String>(&with_prefix("reasoning_effort")) {
             self.reasoning_effort = v;
         }
-        if let Ok(v) = env::var(with_prefix("global_tools"))
-            && let Ok(v) = serde_json::from_str(&v)
-        {
-            self.global_tools = v;
+        if let Ok(v) = env::var(with_prefix("global_tools")) {
+            match serde_json::from_str(&v) {
+                Ok(v) => self.global_tools = v,
+                Err(err) => {
+                    debug!("Ignoring malformed global_tools env override for agent '{name}': {err}")
+                }
+            }
         }
         if let Ok(v) = env::var(with_prefix("global_hooks")) {
             match serde_json::from_str(&v) {