feat(v0.6): show CLAUDE.md on the project detail page + /init generate/update button

The detail page now reads <repo>/CLAUDE.md and shows it in a scrollable
monospace box, with one smart button: "↻ Update" when it exists / "✨ Generate"
when it doesn't. The button opens an interactive Claude session in the repo
running /init (claude "/init") so you review what it writes — reuses the project
launcher, no new backend orchestration, stays a byte-shuttle.

- ProjectDetail += hasClaudeMd / claudeMd; buildProjectDetail reads CLAUDE.md
  (truncated 64KB, best-effort, in the existing Promise.all)
- renderProjectDetail: CLAUDE.md section (content box or empty state) + button
- style.css: .proj-section-row / .proj-claudemd-btn / .proj-claudemd

Tests +5 (458): backend read present/absent; frontend content+Update,
empty+Generate, button opens `claude "/init"`. Verified: tsc clean, full suite
green, build OK, curl returns the content, in-browser shows the box + button.

public/style.css

@@ -1278,6 +1278,49 @@ body {
   text-transform: uppercase;
   color: var(--text-faint);
 }
+/* Section header with an inline action (CLAUDE.md generate/update). */
+.proj-section-row {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+  margin: 22px 0 10px;
+}
+.proj-section-row .proj-section-title {
+  margin: 0;
+}
+.proj-claudemd-btn {
+  flex: none;
+  background: var(--surface-2);
+  border: 1px solid var(--border-strong);
+  color: var(--accent);
+  border-radius: 7px;
+  padding: 6px 12px;
+  font: inherit;
+  font-size: 12px;
+  font-weight: 600;
+  cursor: pointer;
+  transition: background 0.12s ease, border-color 0.12s ease;
+}
+.proj-claudemd-btn:hover {
+  background: var(--accent-soft);
+  border-color: var(--accent);
+}
+.proj-claudemd {
+  margin: 0;
+  max-height: 320px;
+  overflow: auto;
+  padding: 12px 14px;
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  font-family: Menlo, Consolas, monospace;
+  font-size: 12px;
+  line-height: 1.5;
+  color: var(--text);
+  white-space: pre-wrap;
+  word-break: break-word;
+}
 /* Worktrees */
 .proj-wt-list {
   display: flex;