fix: review the saved plan before execution

Present the saved, self-reviewed plan for human review before implementation.
Request an execution method when none was supplied; preserve an existing
choice and ask only for plan review when the human already chose a method.

This completes the shared-intent repair without interpreting approval of an
earlier idea or scope as approval of an unseen implementation plan. Four
saved-plan smoke cases covered old/new wording with/without a prior choice;
all passed the narrower handoff checks, including old controls, so this is
not evidence of measured improvement.

Jesse requested consolidation into two commits and removal of the supporting
spec/plan research content from the PR. The skill bytes remain identical to
the reviewed branch; the complete research and original history are retained
in local archives.

skills/brainstorming/SKILL.md

@@ -11,12 +11,48 @@ Start by classifying how much process the request needs, then work
 through your path: understand the context, refine the idea, present a
 design, and get your human partner's approval.
 
+## Establish Shared Understanding
+
+The outcome of brainstorming is an understanding your human partner can
+recognize and correct, grounded in what they want to accomplish.
+
+1. **Discover intent.** Use the request and available context to identify
+   the intended outcome, who it is for, and what success looks like. When
+   that information is missing, ask one focused question about purpose or
+   intended use before proposing features or an approach. Knowing the app
+   genre does not tell you why your partner wants it. Gathering missing
+   requirements does not ask them to authorize the task again.
+2. **Write back your understanding.** Summarize the intended outcome,
+   relevant constraints, and success criteria in a short note your partner
+   can assess. Separate what they said from assumptions. Invite correction
+   and incorporate their answer before treating this as the design brief.
+3. **Carry intent into the design.** Preserve the agreed understanding in
+   the selected path's design artifact: the written spec for architectural
+   work, or the in-chat design/probe for bounded work and spikes. Check
+   proposed features and technical choices against that understanding.
+
+When the request already supplies the purpose and constraints, reflect
+that understanding instead of asking the same questions again. Keep the
+note concise; its accuracy and the opportunity to correct it matter.
+
 <HARD-GATE>
-Do NOT invoke any implementation skill, write any code, scaffold any
-project, or take any implementation action until you have told your
-human partner what you intend and they have approved it. This applies
-to EVERY task on EVERY path below — the ceremony scales with the task;
-the approval gate never does.
+Before taking any implementation action, including invoking an
+implementation skill, writing product code, scaffolding, installing
+product dependencies, or creating an external project, complete the
+selected path's prerequisites:
+
+- Spike: the human partner approves the question and probe.
+- Bounded: the human partner approves the short in-chat design.
+- Architectural: the human partner reviews and approves the written spec,
+  then reviews the written implementation plan and selects its execution
+  method. Conversational design approval only permits writing the spec;
+  written-spec approval only permits invoking writing-plans.
+
+A reply approves the stage actually presented. Approval of an idea or
+feature scope does not approve artifacts that do not exist yet. Resume
+at the earliest incomplete stage; do not turn one approval into permission
+to skip the rest of the selected path. Read-only project exploration is
+allowed while those prerequisites remain incomplete.
 </HARD-GATE>
 
 ## Three Paths
@@ -53,18 +89,17 @@ stop, say so, and step up. Nothing downgrades mid-task.
 
 ## Anti-Pattern: "Too Simple To Need Approval"
 
-Every path ends with your human partner approving your intent before
-implementation. A todo list, a single-function utility, a config
-change — the design may be two sentences in chat, but you MUST present
-it and get approval. "Simple" tasks are where unexamined assumptions
-cause the most wasted work. What scales with simplicity is the
-artifact, never the approval.
+Every path ends with your human partner approving the required design
+before implementation. A bounded change may need only two sentences in
+chat. A new todo-list project is architectural and requires the written
+spec and planning handoffs. Scale the artifact to the selected path;
+complete that path's reviews before implementation.
 
 ## Red Flags
 
 | Thought | Reality |
 |---------|---------|
-| "This is too simple to need a design" | Simple means a short design, not no design. Two sentences in chat, then approval. |
+| "This is too simple to need a design" | Follow the selected path: a bounded change gets a short chat design; an architectural change gets the written spec and planning handoffs. |
 | "I'll call it bounded and skip the spec" | Reaching for a label to skip work IS the doubt — take the heavier path. |
 | "It's bounded and the design is obvious — I'll start while they read it" | The gate is the approval, not the design's length. Present, then stop until you hear yes. |
 | "I understand this kind of app, so it's bounded" | Bounded measures the repo, not your familiarity. A new project has no existing flow — it is architectural. |

skills/writing-plans/SKILL.md

@@ -152,15 +152,25 @@ If you find issues, fix them inline. No need to re-review — just fix and move
 
 ## Execution Handoff
 
-After saving the plan, offer execution choice:
+After saving and self-reviewing the plan, link it for your human partner
+to read. If they have already explicitly supplied an execution method, ask
+them to review the plan and confirm it captures what they want; wait for that
+review before implementation, then use the preserved method. Otherwise, ask
+them to review the plan and choose an execution method before implementation.
 
-**"Plan complete and saved to `docs/superpowers/plans/<filename>.md`. Two execution options:**
+**When no execution method has already been supplied:**
+
+**"Plan complete and saved to `docs/superpowers/plans/<filename>.md`. Please review the plan. Two execution options:**
 
 **1. Subagent-Driven (recommended)** - I dispatch a fresh subagent per task, review between tasks, fast iteration
 
 **2. Inline Execution** - Execute tasks in this session using executing-plans, batch execution with checkpoints
 
-**Which approach?"**
+**Does the plan capture what you want, and which approach should we use?"**
+
+**When an execution method has already been supplied:**
+
+**"Plan complete and saved to `docs/superpowers/plans/<filename>.md`. Please review the plan. Does it capture what you want?"**
 
 **If Subagent-Driven chosen:**
 - **REQUIRED SUB-SKILL:** Use superpowers:subagent-driven-development