feat: **1. `src/main/db/schema.ts`** — add `settings` table … (+10 more)

- ✅ **1. `src/main/db/schema.ts`** — add `settings` table to `initSchema`
- ✅ **2. `src/main/db/settings.ts`** — create file with `getSetting`, `getSettings`, `setSetting`, `deleteSetting`
- ✅ **3. `src/main/claude/phases.ts`** — add `customSystemPrompt?` param to `getPhaseConfig`; add `getDefaultSystemPromptTemplate` export
- ✅ **4. `src/main/claude/index.ts`** — import `getSetting`; load custom prompt in `sendMessage`; pass to `getPhaseConfig`
- ✅ **5. `src/main/ipc/handlers.ts`** — import `settingsDb` + `getDefaultSystemPromptTemplate`; register `settings:get`, `settings:set`, `settings:delete`, `settings:getDefaultPrompts`
- ✅ **6. `src/main/preload.ts`** — add `getSettings`, `setSetting`, `deleteSetting`, `getDefaultSystemPrompts` to interface + api object
- ✅ **7. `renderer/src/styles/globals.css`** — append all new CSS rules
- ✅ **8. `renderer/src/components/settings/SystemPromptsSettings.tsx`** — create file (new directory)
- ✅ **9. `renderer/src/components/SettingsPage.tsx`** — create file
- ✅ **10. `renderer/src/components/Header.tsx`** — add `onOpenSettings` prop + ⚙ button
- ✅ **11. `renderer/src/App.tsx`** — add `showSettings` state; import + render `<SettingsPage>`; pass `onOpenSettings` to Header

1 files changed, 213 insertions, 0 deletions

diff --git a/renderer/src/styles/globals.css b/renderer/src/styles/globals.css
index ef0275e..61a37c0 100644
--- a/renderer/src/styles/globals.css
+++ b/renderer/src/styles/globals.css
@@ -692,3 +692,216 @@ html[data-theme="light"] .chat-input input:focus {
   border-left: 3px solid var(--accent);
   border-radius: 0 2px 2px 0;
 }
+
+/* ── Settings Overlay ────────────────────────────────────────── */
+.settings-overlay {
+  position: fixed;
+  inset: 0;
+  background: var(--bg-primary);
+  z-index: 100;
+  display: flex;
+  flex-direction: column;
+}
+
+.settings-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 10px 16px;
+  background: var(--bg-secondary);
+  border-bottom: 1px solid var(--border);
+  -webkit-app-region: drag;
+}
+
+.settings-header-left {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  -webkit-app-region: no-drag;
+}
+
+.settings-title {
+  font-size: 12px;
+  font-weight: 700;
+  letter-spacing: 0.15em;
+  text-transform: uppercase;
+  color: var(--text-primary);
+}
+
+.settings-close {
+  background: transparent;
+  border: 1px solid var(--border);
+  border-radius: 2px;
+  color: var(--text-primary);
+  cursor: pointer;
+  font-size: 14px;
+  padding: 4px 9px;
+  font-family: inherit;
+  -webkit-app-region: no-drag;
+  transition: background 0.15s;
+}
+
+.settings-close:hover {
+  background: var(--bg-tertiary);
+}
+
+.settings-body {
+  flex: 1;
+  display: flex;
+  overflow: hidden;
+}
+
+/* ── Settings Side Nav ───────────────────────────────────────── */
+.settings-nav {
+  width: 180px;
+  background: var(--bg-secondary);
+  border-right: 1px solid var(--border);
+  padding: 16px 0;
+  flex-shrink: 0;
+}
+
+.settings-nav-item {
+  display: block;
+  width: 100%;
+  text-align: left;
+  padding: 8px 16px;
+  background: none;
+  border: none;
+  border-left: 2px solid transparent;
+  cursor: pointer;
+  font-family: inherit;
+  font-size: 12px;
+  letter-spacing: 0.05em;
+  color: var(--text-secondary);
+  transition: background 0.1s, color 0.1s;
+}
+
+.settings-nav-item:hover {
+  background: var(--bg-tertiary);
+  color: var(--text-primary);
+}
+
+.settings-nav-item.active {
+  color: var(--text-primary);
+  border-left-color: var(--accent);
+  background: var(--bg-tertiary);
+}
+
+/* ── Settings Content Area ───────────────────────────────────── */
+.settings-content {
+  flex: 1;
+  overflow-y: auto;
+  padding: 32px 40px;
+  max-width: 860px;
+}
+
+.settings-section-title {
+  font-size: 13px;
+  font-weight: 700;
+  letter-spacing: 0.1em;
+  text-transform: uppercase;
+  color: var(--text-primary);
+  margin-bottom: 6px;
+}
+
+.settings-section-desc {
+  font-size: 12px;
+  color: var(--text-secondary);
+  line-height: 1.6;
+  margin-bottom: 24px;
+}
+
+/* ── Phase Tab Strip ─────────────────────────────────────────── */
+.settings-tabs {
+  display: flex;
+  border-bottom: 1px solid var(--border);
+  margin-bottom: 16px;
+}
+
+.settings-tab {
+  padding: 6px 16px;
+  background: none;
+  border: none;
+  border-bottom: 2px solid transparent;
+  margin-bottom: -1px;
+  cursor: pointer;
+  font-family: inherit;
+  font-size: 11px;
+  letter-spacing: 0.07em;
+  text-transform: uppercase;
+  color: var(--text-secondary);
+  transition: color 0.1s;
+}
+
+.settings-tab:hover {
+  color: var(--text-primary);
+}
+
+.settings-tab.active {
+  color: var(--accent);
+  border-bottom-color: var(--accent);
+}
+
+/* ── Prompt Textarea ─────────────────────────────────────────── */
+.settings-textarea {
+  width: 100%;
+  min-height: 420px;
+  padding: 14px;
+  background: var(--bg-secondary);
+  border: 1px solid var(--border);
+  border-radius: 2px;
+  color: var(--text-primary);
+  font-family: inherit;
+  font-size: 12px;
+  line-height: 1.7;
+  resize: vertical;
+  transition: border-color 0.15s, box-shadow 0.15s;
+}
+
+.settings-textarea:focus {
+  outline: none;
+  border-color: var(--accent);
+  box-shadow: 0 0 0 2px rgba(96, 165, 250, 0.15);
+}
+
+html[data-theme="light"] .settings-textarea:focus {
+  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.15);
+}
+
+.settings-textarea.is-custom {
+  border-color: var(--warning);
+}
+
+/* ── Settings Actions Row ────────────────────────────────────── */
+.settings-actions {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  margin-top: 12px;
+}
+
+.settings-custom-badge {
+  margin-left: auto;
+  font-size: 10px;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--warning);
+}
+
+/* ── Header Settings Button ──────────────────────────────────── */
+.settings-btn {
+  padding: 5px 8px;
+  background: transparent;
+  border: 1px solid var(--border);
+  border-radius: 2px;
+  color: var(--text-secondary);
+  cursor: pointer;
+  font-size: 14px;
+  font-family: inherit;
+  transition: background 0.15s, color 0.15s;
+}
+
+.settings-btn:hover {
+  background: var(--bg-tertiary);
+  color: var(--text-primary);
+}