Implement the 011-quick-hp-input feature that adds an inline damage/heal numeric input per combatant row with mode toggle, keyboard workflow, and visual distinction

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

specs/011-quick-hp-input/plan.md

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+# Implementation Plan: Quick HP Input
+
+**Branch**: `011-quick-hp-input` | **Date**: 2026-03-05 | **Spec**: [spec.md](./spec.md)
+**Input**: Feature specification from `/specs/011-quick-hp-input/spec.md`
+
+## Summary
+
+Add an always-visible inline quick HP input per combatant that allows the game master to type a damage or healing number and immediately apply it as a delta to current HP. The domain layer already provides `adjustHp(encounter, combatantId, delta)` with full clamping logic, so no domain or application changes are needed. This is a UI-only feature: a new `QuickHpInput` component in the web adapter layer with damage/heal mode toggle, keyboard-driven workflow, and clear visual distinction between modes.
+
+## Technical Context
+
+**Language/Version**: TypeScript 5.8 (strict mode, verbatimModuleSyntax)
+**Primary Dependencies**: React 19, Vite 6, Tailwind CSS v4, shadcn/ui-style components, Lucide React (icons)
+**Storage**: N/A (no storage changes -- existing localStorage persistence handles HP via `adjustHpUseCase`)
+**Testing**: Vitest (domain pure-function tests); UI component tested via existing patterns
+**Target Platform**: Browser (single-user, local-first)
+**Project Type**: Web application (monorepo: packages/domain, packages/application, apps/web)
+**Performance Goals**: N/A (single-user, instant local state updates)
+**Constraints**: Must follow layered architecture (domain -> application -> adapters); UI-only changes in apps/web
+**Scale/Scope**: Single combatant row component enhancement
+
+## Constitution Check
+
+*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*
+
+| Principle | Status | Notes |
+|-----------|--------|-------|
+| I. Deterministic Domain Core | PASS | No domain changes. Existing `adjustHp` is a pure function. |
+| II. Layered Architecture | PASS | All changes are in the adapter layer (apps/web). Domain and application layers unchanged. |
+| III. Agent Boundary | N/A | No agent features involved. |
+| IV. Clarification-First | PASS | Clarifications completed in spec (visibility model, direct entry coexistence). |
+| V. Escalation Gates | PASS | All requirements are in the spec. |
+| VI. MVP Baseline Language | PASS | Exclusions use "MVP baseline does not include" phrasing. |
+| VII. No Gameplay Rules | PASS | No gameplay mechanics in constitution. |
+
+## Project Structure
+
+### Documentation (this feature)
+
+```text
+specs/011-quick-hp-input/
+├── spec.md
+├── plan.md              # This file
+├── research.md          # Phase 0 output
+├── data-model.md        # Phase 1 output
+├── quickstart.md        # Phase 1 output
+└── tasks.md             # Phase 2 output (via /speckit.tasks)
+```
+
+### Source Code (repository root)
+
+```text
+apps/web/src/
+├── components/
+│   ├── combatant-row.tsx          # Modified: integrate QuickHpInput
+│   ├── quick-hp-input.tsx         # NEW: inline damage/heal input component
+│   └── ui/
+│       ├── button.tsx             # Existing (may use for toggle)
+│       └── input.tsx              # Existing (base input styling)
+├── hooks/
+│   └── use-encounter.ts           # Unchanged (adjustHp already exposed)
+└── App.tsx                        # Unchanged (props already passed through)
+
+packages/domain/src/
+├── adjust-hp.ts                   # Unchanged (already supports +/- deltas)
+├── set-hp.ts                      # Unchanged
+├── types.ts                       # Unchanged
+└── __tests__/
+    └── adjust-hp.test.ts          # Unchanged (domain logic covered)
+
+packages/application/src/
+├── adjust-hp-use-case.ts          # Unchanged
+└── ports.ts                       # Unchanged
+```
+
+**Structure Decision**: UI-only change. Single new component (`quick-hp-input.tsx`) added to the existing component directory. `combatant-row.tsx` modified to integrate it alongside the existing direct HP entry. No new directories needed.
+
+## Complexity Tracking
+
+No violations to justify. All changes are within the existing adapter layer, using established patterns.