refine: generalize workflow to support any subset of capabilities

SKILL.md:
- Workflow header: remove transcription-specific example, state generically
  that users may need any subset of capabilities
- When to Use: add 3 more standalone use cases (transcription, visual
  analysis, material search), with generalizing statement
- Verification checklist: replace specific skip conditions with generic
  'skip if not relevant to the user's request'

SKILL.md

@@ -28,13 +28,17 @@ The skill is **agent-driven, not scripted**: it provides tools (transcription, c
 - User asks "help me edit this video" or "what parts should I cut from this recording."
 - User needs to understand video content beyond what the transcript alone reveals.
 - User wants an iterative dialogue to refine an edit plan over multiple turns.
-- User only needs audio transcription from a video file (extract audio tracks to text). This is a valid standalone use case — not every session requires the full workflow.
+- User only needs audio transcription from a video file.
+- User needs to extract and analyze specific video segments visually.
+- User needs help finding stock materials (stickers, GIFs, meme clips) for editing.
+
+Any subset of these capabilities is a valid use case — not every session requires the full workflow.
 
 **Don't use for:** actual video editing/rendering (this skill plans and transcribes, it does not produce rendered video files).
 
 ## Workflow
 
-**Every step is optional.** The steps below describe the full end-to-end workflow, but the agent should only execute the steps relevant to the user's request. For example, if the user only wants transcription, execute Steps 1, 2, 4, 5 and stop — no editing goal, frame extraction, vision analysis, or edit plan is needed. Use the user's request to determine which steps apply; do not force the full pipeline when it is not needed.
+**Every step is optional.** The steps below describe the full end-to-end workflow, but the agent should only execute the steps relevant to the user's request. Users may need any subset of these capabilities — transcription only, frame extraction only, material search only, or a full planning session. Use the user's request to determine which steps apply; do not force the full pipeline when it is not needed.
 
 ### Step 1 — Check dependencies
 
@@ -339,14 +343,14 @@ This creates an isolated venv with `funasr`, `torch`, `torchaudio`. If the user
 
 ## Verification checklist
 
-Check only the items relevant to the steps actually executed. Not all items apply to every session.
+Check only the items relevant to the steps actually executed. Not all items apply to every session — the user may only need a subset of the skill's capabilities.
 
 - [ ] Dependencies (ffmpeg, uv, python3) confirmed present or user declined. *(Step 1 — always required)*
-- [ ] Video path and audio track index(es) confirmed. *(Step 2 — always required)*
-- [ ] User's editing goal understood. *(Step 3 — skip if user only wants transcription)*
+- [ ] Video path and audio track index(es) confirmed. *(Step 2 — required when video processing is needed)*
+- [ ] User's editing goal understood. *(Step 3 — skip if not relevant to the user's request)*
 - [ ] Transcription completed for all requested tracks, or reused from cache. *(Step 4)*
 - [ ] Index file initialized at `<video_dir>/<video_stem>.vedit.db`. *(Step 5 — always required when any processing is done)*
 - [ ] All extracted clips and frames recorded in the index. *(Step 6 — only if frames were extracted)*
 - [ ] Vision analysis performed where needed. *(Step 7 — only if frames were extracted)*
-- [ ] Edit plan produced as Markdown table with overall recommendation. *(Step 8 — skip if user only wants transcription)*
+- [ ] Edit plan produced as Markdown table with overall recommendation. *(Step 8 — skip if not relevant to the user's request)*
 - [ ] User invited to iterate. *(Step 9)*