fix(sync): clean up stale context.expanded.md when markers removed

CLAUDE.md

@@ -86,7 +86,7 @@ Profiles ([content/profiles/](content/profiles/)) are YAML files that tag which
 
 **Independent sync categories** run in parallel after the archive fetch: `events`, `youtube`, `news`, `discovery`, `tutorials`, `learning`. Each has its own TTL in `config.yaml`. The `news` category (default 2h) uses `runNewsFetch` which tries RSS with retry → YouTube API v3 → baseline file fallback, then caches to `<cacheDir>/news/news-cache.json`.
 
-**Phase 2 — Dynamic Content Expansion:** After the zip fetch, `sync` scans each `context.md` for `<!-- sap-devs:fetch ... -->` markers via `ScanMarkers()`, fetches remote content in parallel (Bubbletea progress UI), then writes `context.expanded.md` alongside `context.md`. `inject` prefers `context.expanded.md` when present. Marker authoring details: [docs/content-authoring.md](docs/content-authoring.md).
+**Phase 2 — Dynamic Content Expansion:** After the zip fetch, `sync` scans each `context.md` for `<!-- sap-devs:fetch ... -->` markers via `ScanMarkers()`, fetches remote content in parallel (Bubbletea progress UI), then writes `context.expanded.md` alongside `context.md`. `inject` prefers `context.expanded.md` when present. When a pack loses all its markers between syncs, `runMarkerExpansion` deletes the previously-written `context.expanded.md` so the loader falls back to the fresh `context.md` instead of serving stale fetched content. Marker authoring details: [docs/content-authoring.md](docs/content-authoring.md).
 
 ### Discovery Center
 

cmd/sync.go

@@ -448,6 +448,17 @@ func runSyncPlain(plan *syncPlan, out io.Writer) error {
 	return nil
 }
 
+// removeStaleExpansion deletes packDir/context.expanded.md if it exists.
+// Used when a pack no longer has sync:fetch markers — without this the loader
+// would keep preferring the stale expansion over the fresh context.md.
+func removeStaleExpansion(packDir string) error {
+	path := filepath.Join(packDir, "context.expanded.md")
+	if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	return nil
+}
+
 // runMarkerExpansion scans all official-layer packs for sync:fetch markers,
 // fetches them in parallel, and writes context.expanded.md alongside each context.md.
 // When p is non-nil, it sends SetMarkersMsg and MarkerDoneMsg to the Bubbletea program.
@@ -488,6 +499,12 @@ func runMarkerExpansion(officialCache string, engine *sapSync.Engine, p *tea.Pro
 		if hasMarkers {
 			packContexts[packID] = contextContent
 			allMarkers = append(allMarkers, markers...)
+		} else {
+			// Pack lost its markers since the previous sync — drop the stale
+			// expanded file so the loader falls back to the fresh context.md.
+			if err := removeStaleExpansion(filepath.Join(packsDir, packID)); err != nil {
+				return fmt.Errorf("clean up stale expansion for %s: %w", packID, err)
+			}
 		}
 	}
 

cmd/sync_test.go

@@ -0,0 +1,41 @@
+package cmd
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRemoveStaleExpansion_DeletesFile(t *testing.T) {
+	packDir := t.TempDir()
+	expandedPath := filepath.Join(packDir, "context.expanded.md")
+	require.NoError(t, os.WriteFile(expandedPath, []byte("stale"), 0644))
+
+	require.NoError(t, removeStaleExpansion(packDir))
+
+	_, err := os.Stat(expandedPath)
+	assert.True(t, os.IsNotExist(err), "context.expanded.md should be gone, got err=%v", err)
+}
+
+func TestRemoveStaleExpansion_NoFileIsNotAnError(t *testing.T) {
+	packDir := t.TempDir()
+	// No context.expanded.md exists.
+	require.NoError(t, removeStaleExpansion(packDir))
+}
+
+func TestRemoveStaleExpansion_LeavesContextMdAlone(t *testing.T) {
+	packDir := t.TempDir()
+	contextPath := filepath.Join(packDir, "context.md")
+	expandedPath := filepath.Join(packDir, "context.expanded.md")
+	require.NoError(t, os.WriteFile(contextPath, []byte("source"), 0644))
+	require.NoError(t, os.WriteFile(expandedPath, []byte("stale"), 0644))
+
+	require.NoError(t, removeStaleExpansion(packDir))
+
+	data, err := os.ReadFile(contextPath)
+	require.NoError(t, err)
+	assert.Equal(t, "source", string(data))
+}

docs/content-authoring.md

@@ -263,6 +263,8 @@ For a plain-text or non-HTML source, use `format="raw"`:
 
 After `sap-devs sync`, the marker is expanded in `context.expanded.md` and the fetched release notes appear directly below it. The original `context.md` is never modified — only the derived `context.expanded.md` changes.
 
+**Removing a marker.** If you delete every `<!-- sync:fetch ... -->` marker from a pack's `context.md`, the next `sap-devs sync` will delete the previously-written `context.expanded.md` for that pack. This ensures the loader falls back to the fresh `context.md` instead of continuing to serve stale fetched content.
+
 For a real-world example see [`content/packs/cap/context.md`](../content/packs/cap/context.md).
 
 ---