feat(FN-4074): add priority option to task creation in engine and extension

Adds task priority support to the task creation flow, spanning the engine runtime (`agent-tools.ts`, `triage.ts`), the CLI extension interface (`extension.ts`), and corresponding documentation and tests. The changeset bumps `@runfusion/fusion` as a minor version.

Fusion-Task-Id: FN-4074

Fusion-Task-Lineage: 726c0ae6-90fb-4c13-ace1-215a2becb2a9

packages/cli/skill/fusion/SKILL.md

@@ -61,7 +61,7 @@ Based on the user's request, route to the appropriate workflow:
 <quick_reference>
 
 **Create a task:**
-Use `fn_task_create` with a descriptive message. Include the problem AND desired outcome.
+Use `fn_task_create` with a descriptive message. Include the problem AND desired outcome, and set `priority` (`low`/`normal`/`high`/`urgent`) when urgency matters.
 
 **List tasks:**
 Use `fn_task_list` to see all tasks grouped by column. Use `column` param to filter.

packages/cli/skill/fusion/references/engine-tools.md

@@ -11,7 +11,7 @@ These tools are **not** part of the user-invokable extension surface. They are i
 
 | Tool | Agent Types | Purpose | Parameters |
 |---|---|---|---|
-| `fn_task_create` | triage, executor, heartbeat | Create a follow-up task from within an agent run | `description` (string), `dependencies?` (string[]) |
+| `fn_task_create` | triage, executor, heartbeat | Create a follow-up task from within an agent run | `description` (string), `dependencies?` (string[]), `priority?` (`low` \| `normal` \| `high` \| `urgent`) |
 | `fn_task_log` | executor, heartbeat | Write significant task log entries | `message` (string), `outcome?` (string) |
 | `fn_task_document_write` | triage, executor, heartbeat | Save/update a named task document revision | `key` (string), `content` (string), `author?` (string) |
 | `fn_task_document_read` | triage, executor, heartbeat | Read one task document or list all | `key?` (string) |

packages/cli/skill/fusion/references/extension-tools.md

@@ -17,6 +17,7 @@ Create a new task on the Fusion task board. The task enters the planning column
 | `description` | string | ✓ | What needs to be done — be descriptive |
 | `depends` | array | — | Task IDs this depends on (e.g. ['FN-001', 'FN-002']) |
 | `agentId` | string | — | Agent ID to assign this task to (e.g. 'agent-abc123') |
+| `priority` | string(enum) | — | Task priority (low, normal, high, urgent) |
 
 ### fn_task_update
 

packages/cli/skill/fusion/workflows/task-management.md

@@ -17,6 +17,7 @@ Use only the public `fn_*` extension tools in this workflow. Do not substitute i
    - Include the problem AND the desired outcome
    - Be specific — the AI triage agent uses your description to write the specification
    - Optionally add dependencies with the `depends` parameter
+   - Optionally set urgency with `priority` (`low`, `normal`, `high`, `urgent`)
 
 2. The task enters **triage** where the AI auto-generates a PROMPT.md with:
    - Steps, file scope, acceptance criteria
@@ -29,7 +30,8 @@ Example:
 ```
 fn_task_create({
   description: "The login form doesn't validate email format before submission. Add client-side email validation that shows an inline error message when the email is invalid. Use the existing form validation pattern from the signup form.",
-  depends: ["FN-042"]
+  depends: ["FN-042"],
+  priority: "high"
 })
 ```