fix(homecore-automation): start engine + implement time/run-mode/choose/template (ADR-161 A3-A7)

A3 (HIGH): homecore-server constructed AutomationEngine then dropped it
immediately while the doc claimed automation was active. Now .start()s the
engine into a long-lived binding (event loop + timer task).

A4 (HIGH): Trigger::Time was hard-coded false with no timer. Added a 1 Hz
wall-clock timer task that fires time: automations when local HH:MM:SS matches
'at' (HH:MM or HH:MM:SS); matches_sync(Time)=false is now correct + documented.

A5 (HIGH): RunMode was documented as AtomicBool-enforced but every trigger
spawned unbounded parallel. Each automation now carries a running AtomicBool;
Single/IgnoreFirst skip re-entrant triggers, Parallel fires every time.
(Bounded Queued/Restart/max → ACCEPTED-FUTURE, honestly stated in the doc.)

A6 (HIGH): Action::Choose discarded choices and always ran default. Now
deserialises each branch's conditions, evaluates them, and runs the first
matching branch; default only if none match.

A7 (MEDIUM): template: conditions were always false in the engine path
(EvalContext built with template_env: None). The engine now builds a
TemplateEnvironment over the state machine and threads it into every
EvalContext (event loop, timer, Choose).

Tests (fail on old source):
- engine_behaviors::time_trigger_fires_via_timer_path (A4)
- engine_behaviors::single_mode_does_not_double_fire_on_rapid_triggers (A5; old fired 2x)
- engine_behaviors::parallel_mode_does_fire_concurrently (A5)
- action::choose_runs_matching_branch_not_default (A6; old ran default)
- engine_behaviors::template_condition_evaluates_true_in_engine (A7; old always false)

engine.rs kept <500 lines; behavioral tests moved to tests/engine_behaviors.rs.

Co-Authored-By: claude-flow <ruv@ruv.net>

v2/crates/homecore-server/src/main.rs

@@ -121,8 +121,21 @@ async fn main() -> Result<()> {
     let _ = plugin_registry; // wired-but-empty at boot; integrations register here
 
     // ── 4. Automation engine ────────────────────────────────────────
-    let _automation_engine = AutomationEngine::new(hc.clone());
-    info!("Automation engine ready (no automations loaded yet)");
+    // Construct AND start the engine (HC-WS-03, ADR-161). `start()`
+    // spawns the state-change event loop + the 1 Hz wall-clock timer
+    // task so state/numeric/event AND time triggers all fire. The
+    // engine is kept alive for the process lifetime (it is moved into a
+    // long-lived binding); its background tasks run until the HomeCore
+    // broadcast channel closes at shutdown. No automations are loaded at
+    // boot yet (YAML loader is P-next); integrations register via
+    // `engine.register(..)`.
+    let automation_engine = AutomationEngine::new(hc.clone());
+    let _automation_task = automation_engine.start();
+    info!(
+        "Automation engine started ({} automations registered) — \
+         state/numeric/event + time triggers active",
+        automation_engine.len()
+    );
 
     // ── 5. Assist pipeline ──────────────────────────────────────────
     let recognizer = RegexIntentRecognizer::new();