ui: split /hosts/{id} into host page + /runs/{runID} run page

Host page owns host metadata, full runs table with per-row stage strip,
in-flight banner, and empty-state CTA. Run page owns pipeline, active
step, logs, sub-steps, spec diffs, and hold banner with a breadcrumb
back to the host. Dashboard tile reverts to host-only.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/store/runs.go

@@ -155,9 +155,8 @@ func (r *Runs) LatestForHost(ctx context.Context, hostID int64) (*model.Run, err
 }
 
 // ListForHost returns the most recent `limit` runs for a host, newest
-// first. Caller uses this to drive the host-detail runs sidebar (last 20
-// by default, Phase 2). Zero/negative limit falls back to a safe cap so
-// a mistaken call can't scan the whole history into memory.
+// first. Zero/negative limit falls back to a safe cap so a mistaken call
+// can't scan the whole history into memory.
 func (r *Runs) ListForHost(ctx context.Context, hostID int64, limit int) ([]model.Run, error) {
 	if limit <= 0 {
 		limit = 20
@@ -193,6 +192,14 @@ func (r *Runs) ListForHost(ctx context.Context, hostID int64, limit int) ([]mode
 	return out, rows.Err()
 }
 
+// ListForHostAll returns every run for a host, newest first. Caps at a
+// defensive 1000 rows so a runaway host that somehow accumulated tens
+// of thousands of runs doesn't blow up the page load; typical hosts
+// finish with < 50.
+func (r *Runs) ListForHostAll(ctx context.Context, hostID int64) ([]model.Run, error) {
+	return r.ListForHost(ctx, hostID, 1000)
+}
+
 // Active returns all runs in non-terminal states.
 func (r *Runs) Active(ctx context.Context) ([]model.Run, error) {
 	rows, err := r.DB.QueryContext(ctx, `