docs(15-03): add agent inbox wireframe summary

Document completion of Plan 15-03 with commit reference and
component specifications for InboxList, MessageCard, MessageDetail,
QuestionForm, OptionGroup, and FreeTextInput.

.planning/phases/15-frontend-wireframes/15-03-SUMMARY.md

@@ -0,0 +1,104 @@
+---
+phase: 15-frontend-wireframes
+plan: 03
+subsystem: ui
+tags: [wireframes, documentation, ascii, inbox, agents, messaging]
+
+# Dependency graph
+requires:
+  - phase: 15-01
+    provides: Wireframe format pattern
+  - phase: 07-question-flow
+    provides: Question/answer flow for agent communication
+provides:
+  - Agent Inbox UI specification
+  - Component contracts (InboxList, MessageCard, MessageDetail, QuestionForm, OptionGroup, FreeTextInput)
+  - Multi-question and multi-select input patterns
+affects: [16-frontend-implementation, ui-components, agent-views]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - Multi-question form rendering with mixed input types
+    - Real-time inbox updates for agent messaging
+
+key-files:
+  created:
+    - docs/wireframes/agent-inbox.md
+  modified: []
+
+key-decisions:
+  - "Filled dot (bullet) = waiting for response, empty circle = informational/done"
+  - "Multi-select uses checkboxes, single-select uses radio buttons"
+  - "Other free-text field auto-selects when user types"
+  - "Notification messages show Dismiss + View Changes buttons"
+
+patterns-established:
+  - "Question forms support mixed question types in single form"
+  - "Message threading via parentMessageId for response correlation"
+
+# Metrics
+duration: 2min
+completed: 2026-02-02
+---
+
+# Phase 15 Plan 03: Agent Inbox Wireframe Summary
+
+**ASCII wireframe documenting the agent inbox UI where users view and respond to agent questions, with support for multi-question forms, radio/checkbox inputs, free-text answers, and notification messages.**
+
+## Performance
+
+- **Duration:** 2 min
+- **Started:** 2026-02-02
+- **Completed:** 2026-02-02
+- **Tasks:** 1
+- **Files modified:** 1
+
+## Accomplishments
+
+- Created comprehensive Agent Inbox wireframe with list and detail views
+- Defined 6 component specifications with props and behavior contracts
+- Documented multiple question types: single-select (radio), multi-select (checkbox), free-text
+- Added empty state, notification messages, and filter/sort options
+- Included TypeScript interfaces for Message, Question, Option, and AgentContext
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Create agent inbox wireframe** - `95c3f5f` (docs)
+
+## Files Created/Modified
+
+- `docs/wireframes/agent-inbox.md` - Agent Inbox wireframe with ASCII art, component specs, interaction notes, data schemas
+
+## Decisions Made
+
+- Visual indicators: filled dot for waiting messages, empty circle for completed/informational
+- Multi-question support allows agents to ask multiple questions in a single message
+- "Other" free-text option auto-selects its radio button when user types
+- Notification messages (task completions) don't require response, show Dismiss and View Changes buttons
+- Real-time updates for new messages with optional desktop notifications
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+
+None.
+
+## User Setup Required
+
+None - no external service configuration required.
+
+## Next Phase Readiness
+
+- All three Phase 15 wireframes complete (dashboard, detail, inbox)
+- Component contracts ready for Phase 16 implementation
+- Interaction patterns documented for frontend development
+
+---
+*Phase: 15-frontend-wireframes*
+*Completed: 2026-02-02*