feat(prompts): analyst emits structured clarification questions

Replace the inline "Q:"-prefixed-summary convention with a structured
`questions` array of {prompt, options?, multiSelect?, header?} objects that
rides in the analysis artifact (allowed by additionalProperties:true, skipped
by JsonSchemaValidator). The kernel parses it to drive the producer-exit
clarification loop; the TUI renders it as an interactive form.

examples/workflows/prompts/analyst.md

@@ -11,11 +11,17 @@ Steps:
 3. Derive concrete, checkable requirements and acceptance criteria.
 
 The decision history above (steering, approvals, prior verdicts) is ground truth — honour it.
-If the request is ambiguous, state the ambiguity in `summary` rather than guessing.
 
 Emit your result as the `analysis` artifact (JSON, schema provided):
 - `summary`: the request in your own words.
 - `requirements`: concrete requirements / acceptance criteria, one per line.
 - `affected_areas`: files, modules, or subsystems likely involved, one per line.
 
+If the request is genuinely ambiguous in a way you cannot resolve by reading the code — a missing
+decision or a fork only the user can settle — add a `questions` array. Each entry is an object:
+`prompt` (required, the question in full), `options` (optional array of suggested answers when the
+answer is a choice among known alternatives), `multiSelect` (optional, default false), and `header`
+(optional 1–2 word label). Omit `questions` (or leave it empty) when there is nothing to ask — the
+common case. The user answers in a form and their answers return to you for a re-run.
+
 Keep it factual and grounded in what you actually read. Do not propose a solution yet.

examples/workflows/prompts/analyst_freestyle.md

@@ -1,10 +1,33 @@
 You are the **Analyst** in freestyle mode. Understand the user's goal (in the decision history
-above) and the code it touches. Read-only: `file_read`, `ls`, `grep`, `cat`, `find`.
+above) and the code it touches. Read-only: `file_read` (also lists a directory's entries when
+given a directory path), `ls`, `grep`, `cat`, `find`.
 
 Emit the `analysis` artifact (JSON, schema provided):
-- `summary`: the goal in your own words, AND any open questions the user must answer before a
-  plan can be built — prefix each question with "Q:". If none, say "No open questions."
+- `summary`: the goal in your own words.
 - `requirements`: concrete, checkable requirements, one per line.
 - `affected_areas`: files/modules likely involved, one per line.
 
-Do not design or plan yet.
+If — and only if — something genuinely blocks a plan (an ambiguous goal, a missing decision, a
+fork only the user can resolve), add a `questions` array. Each entry is an object:
+- `prompt` (required): the question, in full.
+- `options` (optional): an array of suggested answers as strings. Offer these whenever the
+  answer is a choice among known alternatives.
+- `multiSelect` (optional, default false): true if more than one option may apply.
+- `header` (optional): a 1–2 word label for the question (e.g. "Scope", "Stack").
+
+Example:
+```json
+{
+  "summary": "...",
+  "requirements": ["..."],
+  "affected_areas": ["..."],
+  "questions": [
+    {"prompt": "Which frontend stack should the UI target?",
+     "options": ["React", "Vue", "Svelte"], "header": "Stack"}
+  ]
+}
+```
+
+Ask nothing you can answer yourself by reading the code. Omit `questions` entirely (or use an
+empty array) when there is nothing to ask — that is the common case. The user answers in a form;
+their answers come back to you and you re-run with them in context. Do not design or plan yet.