Implement the 014-inline-hp-delta feature that replaces the damage/heal mode toggle with explicit action buttons and Enter-to-damage keyboard shortcut

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

specs/014-inline-hp-delta/quickstart.md

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+# Quickstart: Inline HP Delta Input
+
+## What changes
+
+One file: `apps/web/src/components/quick-hp-input.tsx`
+
+The QuickHpInput component is refactored from a mode-toggle design to an explicit-button design:
+
+**Before** (011-quick-hp-input):
+- Mode toggle button (Sword/Heart icon) + numeric input
+- User switches mode, then types number, then presses Enter
+- Mode state determines whether delta is positive or negative
+
+**After** (014-inline-hp-delta):
+- Numeric input + damage button (Sword) + heal button (Heart)
+- Enter key always applies damage (negative delta)
+- Damage button applies damage (negative delta)
+- Heal button applies healing (positive delta)
+- No mode state
+
+## How to implement
+
+1. Remove the `mode` state variable and the toggle button
+2. Replace with two action buttons (damage + heal) alongside the input
+3. Enter key handler calls `onAdjustHp(combatantId, -n)` (always damage)
+4. Damage button calls `onAdjustHp(combatantId, -n)`
+5. Heal button calls `onAdjustHp(combatantId, +n)`
+6. Remove Tab key override (restore default browser behavior)
+7. Clear input after any successful apply
+
+## How to verify
+
+```bash
+pnpm check    # Must pass (knip + format + lint + typecheck + test)
+```
+
+Manual verification:
+1. Set a combatant's max HP to 20 (currentHp initializes to 20)
+2. Type 7 in the delta input, press Enter → HP should show 13
+3. Type 5 in the delta input, click heal button → HP should show 18
+4. Type 3 in the delta input, click damage button → HP should show 15
+5. Verify input clears after each action
+6. Verify no mode toggle exists in the UI