feat(issue-553): improve draft PR body with issue context and Fixes keyword

- Make PRManager.issuePrefix public for LoomManager access
- Draft PR body now includes issue title, body, and uses Fixes keyword
- Uses configured issue prefix instead of hardcoded #
- Update tests for new draft PR body format

Author: acreeger

.iloom/settings.json

@@ -12,7 +12,7 @@
   "agents": {
     "iloom-issue-analyzer": { "model": "opus" },
     "iloom-issue-planner": { "model": "opus", "review": true },
-    "iloom-issue-analyze-and-plan": { "model": "opus" },
+    "iloom-issue-analyze-and-plan": { "model": "opus", "review": true },
     "iloom-issue-implementer": { "model": "opus" },
     "iloom-code-reviewer": { "providers": { "gemini": "gemini-3-pro-preview" } },
     "iloom-artifact-reviewer": { "enabled": true, "providers": { "gemini": "gemini-3-pro-preview" } }

src/lib/LoomManager.test.ts

@@ -125,6 +125,7 @@ vi.mock('./PRManager.js', () => {
     PRManager: class MockPRManager {
       createDraftPR = mockCreateDraftPR
       checkForExistingPR = mockCheckForExistingPR
+      issuePrefix = '#'
     },
   }
 })
@@ -530,7 +531,7 @@ describe('LoomManager', () => {
       expect(mockCreateDraftPR).toHaveBeenCalledWith(
         expect.any(String), // branch name
         'Test Linear Issue', // PR title from issue
-        expect.stringContaining('PR for issue'), // PR body
+        expect.stringContaining('Fixes #123'), // PR body with Fixes keyword and issue prefix
         expectedPath // worktree path
       )
 

src/lib/LoomManager.ts

@@ -276,9 +276,13 @@ export class LoomManager {
         // For issue mode: use issue title and reference issue number
         // For branch mode: use branch name and generic description
         const prTitle = issueData?.title ?? `Work on ${branchName}`
-        const prBody = input.type === 'issue'
-          ? `PR for issue #${input.identifier}\n\nThis PR was created automatically by iloom.`
-          : `Branch: ${branchName}\n\nThis PR was created automatically by iloom.`
+        let prBody: string
+        if (input.type === 'issue') {
+          const issueBody = issueData?.body ? `\n\n## ${issueData.title}\n\n${issueData.body}` : ''
+          prBody = `Fixes ${prManager.issuePrefix}${input.identifier}${issueBody}\n\n---\n*This PR was created automatically by iloom.*`
+        } else {
+          prBody = `Branch: ${branchName}\n\n---\n*This PR was created automatically by iloom.*`
+        }
 
         // Create draft PR
         getLogger().info('Creating draft PR...')

src/lib/PRManager.ts

@@ -25,7 +25,7 @@ export class PRManager {
 	/**
 	 * Get the issue prefix from the configured provider
 	 */
-	private get issuePrefix(): string {
+	public get issuePrefix(): string {
 		const providerType = this.settings.issueManagement?.provider ?? 'github'
 		const provider = IssueManagementProviderFactory.create(providerType)
 		return provider.issuePrefix