feat(setup): quick onboarding, preserve .env vars, clean up boot logging (#821)

* feat(setup): quick onboarding, preserve .env vars, clean up boot logging (#751, #674)

- Add upsert_bootstrap_vars() to preserve user-added .env vars on re-onboarding
- Add --quick mode: auto-defaults DB + security, asks only LLM provider (2 steps)
- Auto-triggered onboarding uses quick mode for near-instant first run
- Fix NEAR AI model fetch to use cloud-api.near.ai when API key is set
- Handle missing WASM tools/channels directories gracefully
- Downgrade all boot/shutdown tracing::info! to debug (boot screen shows user output)

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

* fix(setup): gate env_backend variable behind postgres feature flag [skip-regression-check]

Clippy lint fix — not a behavioral change, just moving a variable declaration
inside the cfg(feature = "postgres") block where it's used.

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

* fix(review): address PR review comments

- WASM loaders: use tokio::fs::metadata, only treat NotFound as empty,
  propagate other IO errors, handle TOCTOU in read_dir
- bootstrap: only ignore NotFound in read_to_string, propagate other errors
- wizard: restore print_info/print_success for migrations in interactive
  mode (gated by !config.quick), keep tracing::debug for diagnostics
- tests: use shared crate::config::helpers::ENV_MUTEX instead of separate
  NEARAI_ENV_MUTEX to prevent cross-test env var races
- README: fix quick mode description to mention model selection, clarify
  auto_setup_database may prompt when DATABASE_URL is set

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

* feat(setup): skip prompts for DATABASE_URL in quick mode [skip-regression-check]

auto_setup_database() now uses DATABASE_URL directly without calling
step_database_postgres() (which prompts for confirmation). Quick mode
should be fully non-interactive when env vars are already set.

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

* fix(cli): update --quick help text to mention model selection [skip-regression-check]

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

---------

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

src/agent/agent_loop.rs

@@ -516,7 +516,7 @@ impl Agent {
                         *slot.write().await = Some(Arc::clone(&engine));
                     }
 
-                    tracing::info!(
+                    tracing::debug!(
                         "Routines enabled: cron ticker every {}s, max {} concurrent",
                         rt_config.cron_check_interval_secs,
                         rt_config.max_concurrent_routines
@@ -538,20 +538,20 @@ impl Agent {
         let routine_engine_for_loop = routine_handle.as_ref().map(|(_, e)| Arc::clone(e));
 
         // Main message loop
-        tracing::info!("Agent {} ready and listening", self.config.name);
+        tracing::debug!("Agent {} ready and listening", self.config.name);
 
         loop {
             let message = tokio::select! {
                 biased;
                 _ = tokio::signal::ctrl_c() => {
-                    tracing::info!("Ctrl+C received, shutting down...");
+                    tracing::debug!("Ctrl+C received, shutting down...");
                     break;
                 }
                 msg = message_stream.next() => {
                     match msg {
                         Some(m) => m,
                         None => {
-                            tracing::info!("All channel streams ended, shutting down...");
+                            tracing::debug!("All channel streams ended, shutting down...");
                             break;
                         }
                     }
@@ -626,7 +626,7 @@ impl Agent {
                 }
                 Ok(None) => {
                     // Shutdown signal received (/quit, /exit, /shutdown)
-                    tracing::info!("Shutdown command received, exiting...");
+                    tracing::debug!("Shutdown command received, exiting...");
                     break;
                 }
                 Err(e) => {
@@ -655,7 +655,7 @@ impl Agent {
         }
 
         // Cleanup
-        tracing::info!("Agent shutting down...");
+        tracing::debug!("Agent shutting down...");
         repair_handle.abort();
         pruning_handle.abort();
         if let Some(handle) = heartbeat_handle {