…-ready tasks

Major improvements:
1. File Organization:
   - All initiative files now organized in specs/<number>-<short-name>/ folders
   - No more messy project root with scattered files
   - Each initiative is self-contained and easy to archive

2. Phase Boundary Clarification:
   - /speckit.specify and /speckit.plan are BRAINSTORMING phases
   - Only create markdown planning documents (no yaml, scripts, or data files)
   - Implementation artifacts created during /speckit.implement phase
   - Added explicit guardrails and reminders throughout templates

3. JIRA-Ready Task Format:
   - Tasks now include: title, owner, estimate, priority
   - Detailed description with business context
   - Acceptance criteria (3-5 specific, measurable items)
   - Deliverable paths, dependencies, and business value
   - Ready to import into JIRA or project management tools

4. Script Updates:
   - Added INITIATIVE_DIR to JSON output in all scripts
   - Both bash and PowerShell scripts updated consistently

5. Documentation:
   - Updated README with folder structure diagram
   - Added phase boundary summary
   - Clarified what gets created in each phase

Fixes #1 - initiative files scattered in project root
Fixes #2 - AI creating implementation files during planning
Fixes #3 - tasks too simple for JIRA import