Review story 1.5: provisioning execution passes all ACs — Epic 1 complete

Fix portal.py error handling so validate_cache failures return retry HTML while
kill_wifi ProvisioningError propagates (re-raise) per AC4. All 56 tests pass.
Update sprint-status.yaml: 1-5 → done, epic-1 → done. Append story 1.5 deferred
items to deferred-work.md.

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

_bmad-output/implementation-artifacts/sprint-status.yaml

@@ -35,7 +35,7 @@
 # - Dev moves story to 'review', then runs code-review (fresh context, different LLM recommended)
 
 generated: 2026-04-22
-last_updated: 2026-04-22  # 1-5 story file created, marked ready-for-dev
+last_updated: 2026-04-22  # 1-5 review complete, epic-1 done
 project: planeMapper
 project_key: NOKEY
 tracking_system: file-system
@@ -43,12 +43,12 @@ story_location: _bmad-output/implementation-artifacts
 
 development_status:
   # Epic 1: Device Setup & Provisioning
-  epic-1: in-progress
+  epic-1: done
   1-1-project-scaffold-and-verified-entry-points: done
   1-2-configuration-read-write-wipe: done
   1-3-wifi-hotspot-and-captive-portal-form: done
   1-4-location-resolution-icao-and-address: done
-  1-5-provisioning-execution-tile-download-cache-validation-and-wifi-kill: review
+  1-5-provisioning-execution-tile-download-cache-validation-and-wifi-kill: done
   epic-1-retrospective: optional
 
   # Epic 2: Live Radar Display