refactor: Major v6 epic creation improvements and documentation overhaul

## Key Changes

### 1. Epic Creation Workflow Enhancements
- Added user-value focused epic structure principles (NO technical layer breakdown)
- Implemented multi-mode detection: CONTINUE, REPLACE, or UPDATE existing epics
- Added comprehensive anti-pattern examples showing wrong vs right epic breakdown
- Epics now created AFTER architecture for technically-informed story breakdown
- Added checkpoint protocol for interactive workflow progression

### 2. Removed Deprecated Solutioning Gate Check
- Deleted entire solutioning-gate-check workflow (682 lines)
- Replaced by new implementation-readiness workflow
- Cleaner separation of concerns in solutioning phase

### 3. PRD Template Simplification
- Removed hardcoded "Implementation Planning", "References", and "Next Steps" sections
- PRD now focuses purely on requirements, not workflow orchestration
- Epics/stories created as separate step after architecture

### 4. Documentation Overhaul (15+ docs updated)
- Updated quick-start guide with v6 workflow sequence
- Clarified that epics are created AFTER architecture, not during PRD
- Updated solutioning docs to reflect implementation-readiness pattern
- Improved agents-guide, brownfield-guide, enterprise docs
- Enhanced glossary, FAQ, and workflow reference documentation

### 5. Workflow Path Adjustments
- All 4 paths updated (enterprise/method × brownfield/greenfield)
- Version bumps across BMGD, BMM, and CIS workflow YAMLs
- Minor instruction file updates for consistency

### Files Changed
- 65 files total: 468 insertions, 978 deletions (net reduction of 510 lines)
- 4 files deleted (entire solutioning-gate-check workflow)
- 1 new directory added (implementation-readiness placeholder)

src/modules/bmb/workflows/create-workflow/workflow-creation-guide.md

@@ -1088,7 +1088,7 @@ input_file_patterns:
     sharded: '{output_folder}/*architecture*/index.md'
 
   document_project:
-    sharded: '{output_folder}/docs/index.md' # Brownfield always uses index
+    sharded: '{output_folder}/index.md' # Brownfield always uses index
 ```
 
 #### 2. Add Discovery Instructions to instructions.md
@@ -1108,7 +1108,7 @@ This workflow requires: [list required documents]
    - Read `index.md` to understand the document structure
    - Read ALL section files listed in the index (or specific sections for selective load)
    - Treat the combined content as if it were a single document
-4. **Brownfield projects**: The `document-project` workflow creates `{output_folder}/docs/index.md`
+4. **Brownfield projects**: The `document-project` workflow creates `{output_folder}/index.md`
 
 **Priority**: If both whole and sharded versions exist, use the whole document.