Refactor PR creation: extract shared partial for create_pr and work_issue prompts

[Helmi]

Description

We have duplicate PR creation logic in both work_issue and create_pr prompts. This creates a maintenance burden and violates DRY principles. We should extract the common PR creation logic into a Handlebars partial that both prompts can use.

Context

• Project area: MCP Server / Prompt Templates
• Related to: Improve work_issue command: add git sync check and remove redundancies #30 (improved work_issue prompt), SQLite database lock error when using log_activity tool #33 (database fixes)
• Complexity: 4/10

Technical Details

• Affected files:
  • mcp-server/src/templates/prompts/create_pr.yaml - Refactor to use new partial
  • mcp-server/src/templates/prompts/work_issue.yaml - Refactor to use new partial
  • mcp-server/src/templates/prompts/partials/_pr_creation.hbs - New partial to create
• Key functions/classes: Handlebars partial system, prompt templates

Requirements

Current Problems

1. Duplicate PR creation logic in two places (maintenance burden)
2. create_pr prompt has prescriptive git commands (against new standards from Improve work_issue command: add git sync check and remove redundancies #30)
3. No single source of truth for PR creation

Proposed Solution

• Extract PR creation logic into a shared Handlebars partial (e.g., _pr_creation.hbs)
• create_pr.yaml keeps its context gathering (fetch issue, analyze changes) then uses partial
• work_issue.yaml skips context gathering (already has it) and uses the partial
• Update create_pr to follow new prompt standards (no prescriptive commands)

Benefits

• Single source of truth for PR creation
• Context-aware usage (create_pr gathers context, work_issue already has it)
• Follows DRY principles
• Uses existing Handlebars infrastructure

Implementation Steps

• Step 1: Create new partial file _pr_creation.hbs in partials directory
• Step 2: Extract common PR creation logic from work_issue.yaml step 6
• Step 3: Define partial interface (expected variables: title, body, issue number, etc.)
• Step 4: Update work_issue.yaml to use {{> pr_creation}} instead of inline logic
• Step 5: Remove prescriptive git commands from create_pr.yaml
• Step 6: Update create_pr.yaml to use {{> pr_creation}} for PR creation
• Step 7: Test both prompts to ensure they still work correctly

Acceptance Criteria

• Single _pr_creation.hbs partial contains all PR creation logic
• Both create_pr and work_issue prompts use the shared partial
• No duplicate PR creation code exists
• create_pr prompt follows new standards (no prescriptive commands)
• Both prompts successfully create PRs when tested
• Partial gracefully handles missing optional parameters

[Helmi]

This refactoring is related to our recent work on improving prompts in #30 and the database fixes in #33. It will help maintain consistency in PR creation across different workflows.

[Helmi]

Might need another check - might be outdated and will definitely need to consider #52 #53 #63