replay ui fix (#56)

* refactor: rename inspect to replay across the codebase

Renames inspect-ui/ to replay-ui/, internal/inspect/ to internal/replay/,
the CLI subcommand from `sanderling inspect` to `sanderling replay`, and
updates all references in docs, Makefile, README, and Go comments.

* feat(replay-ui): show spec filename with full path on hover

RunList and RunDetail now render the basename of spec_path (e.g.
login.spec.ts) with the full path available as a title tooltip.

replay-ui/src/panels/Screenshot.css

@@ -0,0 +1,40 @@
+.screenshot-frame {
+  position: relative;
+  width: 100%;
+  max-width: 100%;
+  max-height: 100%;
+  margin: 0 auto;
+  background: var(--surface);
+  overflow: hidden;
+}
+
+.screenshot-image {
+  display: block;
+  width: 100%;
+  height: 100%;
+  object-fit: contain;
+}
+
+.screenshot-overlay {
+  position: absolute;
+  inset: 0;
+  width: 100%;
+  height: 100%;
+  pointer-events: none;
+}
+
+.screenshot-placeholder {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 100%;
+  height: 100%;
+  min-height: 240px;
+  background: var(--surface);
+  border: 1px dashed var(--border-strong);
+  color: var(--text-muted);
+  font-family: var(--font-mono);
+  font-size: 12px;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+}