fix: quote YAML values in Task schema frontmatter to prevent parse errors

Unquoted values containing commas (e.g. `description: string, what needs
to be done`) caused basic-memory's YAML parser to reject the frontmatter
on seed. Matches the quoting style already used in conversation-schema.ts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: bm-clawd

schema/task-schema.ts

@@ -8,16 +8,16 @@ type: schema
 entity: Task
 version: 1
 schema:
-  description: string, what needs to be done
-  status?(enum): [active, blocked, done, abandoned], current state
-  assigned_to?: string, who is working on this
-  steps?(array): string, ordered steps to complete
-  current_step?: integer, which step number we're on (1-indexed)
-  context?: string, key context needed to resume after memory loss
-  started?: string, when work began
-  completed?: string, when work finished
-  blockers?(array): string, what's preventing progress
-  parent_task?: Task, parent task if this is a subtask
+  description: "string, what needs to be done"
+  status?(enum): "[active, blocked, done, abandoned], current state"
+  assigned_to?: "string, who is working on this"
+  steps?(array): "string, ordered steps to complete"
+  current_step?: "integer, which step number we're on (1-indexed)"
+  context?: "string, key context needed to resume after memory loss"
+  started?: "string, when work began"
+  completed?: "string, when work finished"
+  blockers?(array): "string, what's preventing progress"
+  parent_task?: "Task, parent task if this is a subtask"
 settings:
   validation: warn
 ---