Enhance proposal guidelines in slash-command-templates.ts (#306)

* Enhance proposal guidelines in slash-command-templates.ts

- Added instructions to avoid writing code during the proposal stage and focus on creating design documents.
- Emphasized the design phase by including a reminder not to implement code until the apply stage.
- Updated validation steps to clarify the importance of confirming project conventions before proceeding with tasks.

* Update proposal guidelines in slash-command-templates.ts to clarify that no implementation code should be written during the design phase.

* Refine proposal and apply steps in slash-command-templates.ts

- Removed redundant instruction in proposal steps to streamline the process.
- Clarified the initial reading order for apply steps by omitting the project conventions document, focusing on the proposal and design documents instead.

Author: jax-max

src/core/templates/slash-command-templates.ts

@@ -5,7 +5,8 @@ const baseGuardrails = `**Guardrails**
 - Keep changes tightly scoped to the requested outcome.
 - Refer to \`openspec/AGENTS.md\` (located inside the \`openspec/\` directory—run \`ls openspec\` or \`openspec update\` if you don't see it) if you need additional OpenSpec conventions or clarifications.`;
 
-const proposalGuardrails = `${baseGuardrails}\n- Identify any vague or ambiguous details and ask the necessary follow-up questions before editing files.`;
+const proposalGuardrails = `${baseGuardrails}\n- Identify any vague or ambiguous details and ask the necessary follow-up questions before editing files.
+- Do not write any code during the proposal stage. Only create design documents (proposal.md, tasks.md, design.md, and spec deltas). Implementation happens in the apply stage after approval.`;
 
 const proposalSteps = `**Steps**
 1. Review \`openspec/project.md\`, run \`openspec list\` and \`openspec list --specs\`, and inspect related code or docs (e.g., via \`rg\`/\`ls\`) to ground the proposal in current behaviour; note any gaps that require clarification.
@@ -16,6 +17,7 @@ const proposalSteps = `**Steps**
 6. Draft \`tasks.md\` as an ordered list of small, verifiable work items that deliver user-visible progress, include validation (tests, tooling), and highlight dependencies or parallelizable work.
 7. Validate with \`openspec validate <id> --strict\` and resolve every issue before sharing the proposal.`;
 
+
 const proposalReferences = `**Reference**
 - Use \`openspec show <id> --json --deltas-only\` or \`openspec show <spec> --type spec\` to inspect details when validation fails.
 - Search existing requirements with \`rg -n "Requirement:|Scenario:" openspec/specs\` before writing new ones.