feat: add craft-goal session starter and command

Adds /craft-goal autocomplete and chat handling for starting a Goal crafting session.
Introduces new Magic Prompts content and localized labels/descriptions for Goal crafting.
Migrates desktop draft starters to include Craft a Goal once and persists the migration marker.

packages/ui/src/lib/magicPrompts.ts

@@ -37,6 +37,8 @@ export type MagicPromptId =
   | 'session.implementationResponseToReviewer.visible'
   | 'session.plan.visible'
   | 'session.plan.instructions'
+  | 'session.craftGoal.visible'
+  | 'session.craftGoal.instructions'
   | 'session.catchup.visible'
   | 'session.catchup.instructions'
   | 'session.debug.visible'
@@ -719,6 +721,73 @@ Run this as a dialogue, not a one-shot answer.
 
 6. When everything is settled, produce the final implementation plan: a clear, ordered breakdown of the work, the files and areas affected, the decisions that were made (and why), known risks, and any remaining assumptions flagged explicitly. The plan must reflect the user's actual answers — never fill gaps with guesses.
 
+Respond in the same language the user uses.`,
+  },
+  {
+    id: 'session.craftGoal.visible',
+    title: 'Goal Crafting Visible Prompt',
+    group: 'Session',
+    description: 'Visible user message sent by the /craft-goal command.',
+    placeholders: [
+      { key: 'idea_block', description: 'Optional initial task or idea supplied after the command.' },
+    ],
+    template: `Help me turn an idea or task into a clear, verifiable Goal.{{idea_block}}`,
+  },
+  {
+    id: 'session.craftGoal.instructions',
+    title: 'Goal Crafting Instructions',
+    group: 'Session',
+    description: 'Hidden instructions attached to the /craft-goal command. Guides discovery and produces a ready-to-use Goal objective.',
+    template: `The user wants help turning a task, idea, or desired outcome into a strong Goal for an autonomous, multi-turn working session.
+
+A Goal is a persistent completion contract, not an implementation plan and not a larger one-shot prompt. Help the user define what "done" means clearly enough that another agent can work toward it, verify it against evidence, continue through uncertain intermediate steps, and stop honestly when completion is blocked.
+
+Run this as a guided dialogue, not a one-shot answer.
+
+1. Start from the user's intent. If the visible message includes an initial idea, use it immediately. Otherwise ask what they want to accomplish. Do not ask them to formulate the Goal themselves.
+
+2. Investigate before asking when context is available. For repository work, inspect relevant code, tests, scripts, documentation, and conventions when that would answer questions or expose constraints. Do not ask for information that can be determined reliably from the workspace.
+
+3. Decide whether a Goal is appropriate. Goals fit work with a durable objective, an evidence-based finish line, and an uncertain or iterative path. If this is a one-off edit, simple explanation, or obvious single step, explain briefly that a normal prompt is likely better. Continue crafting a Goal if the user still wants one.
+
+4. Resolve the Goal contract:
+- Outcome: what must be true when the work is complete.
+- Verification surface: which tests, benchmarks, commands, artifacts, source material, observations, or other evidence prove completion.
+- Constraints: what behavior, quality, compatibility, safety, performance, or scope must remain intact.
+- Boundaries: which files, systems, tools, data, repositories, environments, or resources may or may not be used.
+- Iteration policy: how the working agent should evaluate evidence and choose the next useful action after each attempt.
+- Blocked stop condition: when it should stop, what evidence and attempted paths it should report, and what input would unlock progress.
+
+5. Ask only necessary questions, in batches of at most 3. Prefer concrete, decision-oriented questions. Distinguish facts found in the workspace from decisions only the user can make.
+
+6. Do not over-prescribe the path. Define the destination, evidence standard, and operating constraints while leaving the working agent room to choose its next action from what it learns.
+
+7. Do not invent precision. Never fabricate targets, commands, environments, acceptance criteria, or scope. When exact criteria are unavailable, define an honest evidence standard that separates confirmed results, approximations, blockers, and remaining uncertainty.
+
+8. Do not implement the task. You may inspect the workspace to understand it, but do not edit files, execute the proposed solution, or begin working toward the Goal. This session's deliverable is the Goal itself.
+
+9. Once the contract is resolved, respond in exactly this structure:
+
+## Proposed Goal
+
+\`\`\`text
+<one self-contained Goal objective ready to paste into the Goal dialog; do not prefix it with /goal>
+\`\`\`
+
+## Why This Is Verifiable
+
+- <brief explanation of the outcome and evidence>
+- <brief explanation of the preserved constraints>
+- <brief explanation of the blocked stop condition>
+
+## Assumptions
+
+- <only assumptions that still matter, or "None">
+
+The proposed Goal should normally be one compact paragraph. Keep enough operational detail to make completion auditable, but remove conversational history, rationale, repetition, and implementation details that are not part of the completion contract.
+
+Do not activate, execute, or claim completion of the proposed Goal. End by inviting the user to revise it or use it in the Goal dialog.
+
 Respond in the same language the user uses.`,
   },
   {