agent v0.26.0: slice 10 P2 activation — POST /guest/reboot (user-triggered)

Self-scoped guest reboot (pct reboot, detached, 202) so an enrolled-into-running-
guest drive's persisted bind activates at next boot. Tests: accepted + cross-guest
403. Pairs with controller v0.49.0 pending-drive detection + "Újraindítás most".

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -3,6 +3,19 @@
 All notable changes to **felhom-agent** are recorded here. Update on every code
 change that gets pushed.
 
+## v0.26.0 — slice 10 P2 activation: guest-reboot endpoint (user-triggered drive activation) (2026-06-12)
+
+A drive enrolled into a RUNNING unprivileged guest can't be live-activated (proven: `pct set` won't
+hot-apply; `/proc/<pid>/root` bind → mount-locking refusal; `nsenter -m` loses the host source). So the
+bind activates at the next guest boot. This adds the user-triggered restart path.
+
+- **`POST /guest/reboot` (`internal/localapi`)** — self-scoped (vmid from token). Runs `pct reboot
+  <vmid>` **detached** (it blocks ~30s until the guest is back) and returns **202** immediately, so the
+  calling controller gets a clean response before the reboot takes it down (the agent is host-side and
+  survives). `GuestBinder.RebootGuest` over the fenced runner. Tests: `TestGuestReboot_Accepted`
+  (202 + RebootGuest invoked for the token's vmid), `TestGuestReboot_CrossGuest403` (body vmid mismatch
+  refused, no reboot). Pairs with controller v0.49.0 (pending-activation detection + "Újraindítás most").
+
 ## v0.25.0 — slice 10 P2: bind enrolled user-data drives into the guest (passthrough) (2026-06-12)
 
 External user-data drives are mounted on the HOST but were never passed INTO the guest (diagnosed