feat(collect): remove power-on/off, add skip-hung for Redfish collection

Remove power-on and power-off functionality from the Redfish collector;
keep host power-state detection and show a warning in the UI when the
host is powered off before collection starts.

Add a "Пропустить зависшие" (skip hung) button that lets the user abort
stuck Redfish collection phases without losing already-collected data.
Introduces a two-level context model in Collect(): the outer job context
covers the full lifecycle including replay; an inner collectCtx covers
snapshot, prefetch, and plan-B phases only. Closing the skipCh cancels
collectCtx immediately — aborts all in-flight HTTP requests and exits
plan-B loops — then replay runs on whatever rawTree was collected.

Signal path: UI → POST /api/collect/{id}/skip → JobManager.SkipJob()
→ close(skipCh) → goroutine in Collect() → cancelCollect().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bible-local/05-collectors.md

@@ -35,18 +35,27 @@ If the collector adds a fallback, probe, or normalization rule, replay must mirr
 
 ### Preflight and host power
 
-- `Probe()` may be used before collection to verify API connectivity and current host `PowerState`
-- if the host is off and the user chose power-on, the collector may issue `ComputerSystem.Reset`
-  with `ResetType=On`
-- power-on attempts are bounded and logged
-- after a successful power-on, the collector waits an extra stabilization window, then checks
-  `PowerState` again and only starts collection if the host is still on
-- if the collector powered on the host itself for collection, it must attempt to power it back off
-  after collection completes
-- if the host was already on before collection, the collector must not power it off afterward
-- if power-on fails, collection still continues against the powered-off host
-- all power-control decisions and attempts must be visible in the collection log so they are
-  preserved in raw-export bundles
+- `Probe()` is used before collection to verify API connectivity and report current host `PowerState`
+- if the host is off, the collector logs a warning and proceeds with collection; inventory data may
+  be incomplete when the host is powered off
+- power-on and power-off are not performed by the collector
+
+### Skip hung requests
+
+Redfish collection uses a two-level context model:
+
+- `ctx` — job lifetime context, cancelled only on explicit job cancel
+- `collectCtx` — collection phase context, derived from `ctx`; covers snapshot, prefetch, and plan-B
+
+`collectCtx` is cancelled when the user presses "Пропустить зависшие" (skip hung).
+On skip, all in-flight HTTP requests in the current phase are aborted immediately via context
+cancellation, the crawler and plan-B loops exit, and execution proceeds to the replay phase using
+whatever was collected in `rawTree`. The result is partial but valid.
+
+The skip signal travels: UI button → `POST /api/collect/{id}/skip` → `JobManager.SkipJob()` →
+closes `skipCh` → goroutine in `Collect()` → `cancelCollect()`.
+
+The skip button is visible during `running` state and hidden once the job reaches a terminal state.
 
 ### Discovery model