feat(settings): add configurable model selection

- Add Model settings section with free-text input for model override
- Pass configured model through to SDK query() calls
- Display active model badge in ActionBar next to token usage
- Seed model state from DB on mount, update from system:init events
- Empty/unset value uses SDK default (no breaking change)

1 files changed, 29 insertions, 0 deletions

diff --git a/renderer/src/styles/globals.css b/renderer/src/styles/globals.css
index 7a8ae45..0db62c2 100644
--- a/renderer/src/styles/globals.css
+++ b/renderer/src/styles/globals.css
@@ -621,6 +621,17 @@ html[data-theme="light"] .chat-input input:focus {
   color: var(--text-secondary);
 }
 
+.model-badge {
+  font-size: 11px;
+  font-family: var(--font-mono, monospace);
+  color: var(--text-secondary);
+  padding: 2px 6px;
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  white-space: nowrap;
+  user-select: none;
+}
+
 .permission-toggle {
   display: flex;
   align-items: center;
@@ -953,6 +964,24 @@ html[data-theme="light"] .settings-textarea:focus {
   border-color: var(--warning);
 }
 
+/* ── Model Input ─────────────────────────────────────────────── */
+.settings-model-input {
+  width: 100%;
+  padding: 6px 8px;
+  background: var(--bg-secondary);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  color: var(--text-primary);
+  font-size: 13px;
+  font-family: var(--font-mono, monospace);
+  box-sizing: border-box;
+  transition: border-color 0.15s;
+}
+.settings-model-input:focus {
+  outline: none;
+  border-color: var(--accent);
+}
+
 /* ── Settings Actions Row ────────────────────────────────────── */
 .settings-actions {
   display: flex;