feat(ui): #25 Phase K.3 — Settings panel + click-to-rebind + Phase K shipped

Phase K final commit. Settings panel with click-to-rebind UX on top of
the K.1+K.2 input architecture, plus the roadmap / ISSUES / memory
updates that retire Phase K.

InputDispatcher gains BeginCapture / CancelCapture / IsCapturing /
SetBindings — modal capture suppresses normal action firing for the
next chord. Esc cancels (returns sentinel default chord); modifier-only
keys don't complete capture; non-modifier key down with current
modifier mask completes.

IPanelRenderer + ImGuiPanelRenderer + FakePanelRenderer gain
BeginMainMenuBar / EndMainMenuBar / BeginMenu / EndMenu / MenuItem
primitives.

SettingsVM owns a draft copy of KeyBindings with explicit Save /
Cancel / Reset semantics. Click-to-rebind enters dispatcher capture
mode; on chord captured, conflict-detect against draft (excluding the
action being rebound itself); surface a ConflictPrompt when the chord
collides; ResolveConflict(replace=true|false) commits or reverts.
ResetActionToDefault restores a single action to RetailDefaults();
ResetAllToDefaults rebuilds the entire draft. Save invokes the
onSave callback (which writes JSON + swaps the live dispatcher's
bindings).

SettingsPanel renders 8 retail-keymap-categorized CollapsingHeader
sections (Movement, Postures, Camera, Combat, UI panels, Chat,
Hotbar, Emotes). Per action: name + current binding(s) summary +
"Rebind"/"Reset" buttons. Conflict prompt at the top when pending.
Save / Cancel / "Reset all to retail defaults" at the top.

GameWindow registers SettingsPanel + wires F11 →
ToggleOptionsPanel → IsVisible toggle, plus a top-of-frame ImGui
MainMenuBar with View → Settings/Vitals/Chat/Debug entries (calls
ImGui directly — the abstraction methods exist for backend
portability but the host doesn't own a menu-bar surface).

Tests: +37 across InputDispatcherCaptureTests (7),
IPanelRendererMainMenuBarTests (9), SettingsVMTests (13),
SettingsPanelTests (8). Solution total 1220 green.

Roadmap (docs/plans/2026-04-11-roadmap.md) appends Phase K shipped
section after Phase J with K.1a–K.3 commit SHAs. ISSUES.md files
Phase L deferred work as #L.1–#L.8 (hotbar UI, spellbook favorites,
combat-mode dispatch, F-key panels, floating chat windows, UI layout
save/load, joystick bindings, plugin input subscription) and adds
#21–#25 to Recently closed. project_input_pipeline.md updated to
shipped state. CLAUDE.md gets an input-pipeline reference.

Closes Phase K.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/plans/2026-04-11-roadmap.md

@@ -246,6 +246,63 @@ the way retail + holtburger expect.
 
 ---
 
+### Phase K — Input architecture + retail bindings + Settings panel
+
+**Goal:** retire the hardcoded WASD-style scheme; ship retail-faithful
+bindings as the default; let users remap any action via an in-game
+Settings panel; auto-enter player mode at login; replace mouse-X-yaw
+with retail's MMB-hold mouse-look.
+
+**Sub-pieces (all ✓ SHIPPED 2026-04-26):**
+
+- **✓ SHIPPED — K.1a — Input architecture skeleton.** Action enum,
+  multicast `InputDispatcher` with scope stack, `KeyChord` /
+  `Binding` / `KeyBindings`, Silk.NET adapters, parallel to existing
+  handlers — no behavior change. Commit `84512d3`.
+- **✓ SHIPPED — K.1b — Cut handlers over to dispatcher.** Drop the
+  legacy mouse-X-character-yaw path, fix `WantCaptureMouse` gating,
+  single input path. Commit `256e962`.
+- **✓ SHIPPED — K.1c — Retail-default keymap + JSON persistence.**
+  ~149 bindings matching
+  `docs/research/named-retail/retail-default.keymap.txt` + JSON
+  load/save with merge-over-defaults migration at
+  `%LOCALAPPDATA%\acdream\keybinds.json`. Acdream debug F-keys
+  relocated to `Ctrl+F*` to avoid retail conflicts. Commit `da18910`.
+- **✓ SHIPPED — K.2 — Login flow + MMB mouse-look + free-fly button.**
+  Auto-enter player mode at login (one-shot guard reusing the existing
+  Tab handler), MMB-hold mouse-look (retail's `CameraInstantMouseLook`
+  — cursor-locked camera + character yaw drive together), `DebugPanel`
+  "Toggle Free-Fly Mode" button, `Tab → ToggleChatEntry →
+  ChatPanel.FocusInput()`. Commit `af74eac`.
+- **✓ SHIPPED — K.3 — Settings panel + Keybindings UI + roadmap/issues
+  update.** `SettingsPanel` with click-to-rebind UX (modal capture
+  via `InputDispatcher.BeginCapture`, Esc cancels, conflict-detection-
+  with-confirmation prompt, draft / Save / Cancel semantics), F11
+  toggle + ImGui MainMenuBar entry, per-action / per-section /
+  reset-all-defaults buttons. Roadmap + ISSUES + memory crib +
+  CLAUDE.md updated in this commit. Commit `(this commit)`.
+
+**Acceptance (verified 2026-04-26):**
+- Login → spawn at the character's actual world position in chase
+  camera (NOT Holtburg orbit). Tab not required.
+- W = run forward; X = run back; A/D = turn; Z/C = strafe;
+  Alt+A/D/Left/Right = strafe (alternate); Q = autorun; Space = jump;
+  Shift = walk modifier; S = stop; Y/G/H/B = postures.
+- Mouse alone does NOT drive character yaw. MMB-hold = cursor-locked
+  camera + character yaw drive together. RMB and LMB are
+  `SelectRight` / `SelectLeft` per retail.
+- F11 / View → Settings opens panel. Click "Rebind" next to any
+  action → press a key → if conflict, prompt. Save writes
+  `%LOCALAPPDATA%\acdream\keybinds.json`. Restart preserves
+  customizations.
+- Mode-dependent combat keys (Insert/PgUp/Delete/End/PgDn) bound but
+  dormant — light up in Phase L when `CombatState.CurrentMode` is
+  wired (issue #L.3).
+
+**Memory crib:** `memory/project_input_pipeline.md`.
+
+---
+
 ### Phase J — Long-tail (deferred / low-priority)
 
 Not detailed here; each gets its own brainstorm when it becomes relevant.