refactor: comprehensive workflow modernization and standardization

## Major Improvements

### 1. Elicitation System Modernization
- Removed legacy `<elicit-required />` tag from workflow.xml
- Replaced with direct `<invoke-task halt="true">{project-root}/bmad/core/tasks/adv-elicit.xml</invoke-task>` pattern
- More explicit, self-documenting, and eliminates indirection layer
- Added strategic elicitation points across all planning workflows:
  - PRD: After success criteria, scope, functional requirements, and final review
  - Create-Epics-And-Stories: After epic proposals and each epic's stories
  - Architecture: After decisions, structure, patterns, implementation patterns, and final doc
  - Updated audit-workflow tag scanner to remove obsolete elicit-required reference

### 2. Input Document Discovery Streamlined
- Replaced verbose 19-line "Input Document Discovery" sections with single critical tag
- New format: `<critical>Input documents specified in workflow.yaml input_file_patterns...</critical>`
- Eliminates duplication - workflow.yaml already defines patterns
- Updated across 6 workflows (PRD, create-epics-and-stories, architecture, tech-spec, UX, gate-check)
- Saved ~114 lines of repeated bloat

### 3. Scale System Migration (Levels 0-4 → 3 Tracks)
- Updated PRD workflow from "Level 0-4" to "Quick Flow / BMad Method / Enterprise Method"
- Changed `project_level` variable to `project_track`
- Removed `target_scale` variable (no longer needed)
- Updated workflow.yaml descriptions to reference tracks not levels
- Updated checklist from "Level 2" and "Level 3-4" to "BMad Method" and "Enterprise Method"
- Aligns with new scale-adaptive-system.md (3-track methodology)

### 4. Epic/Story Template Standardization
- Replaced hardcoded 8-epic template with clean repeating pattern using N/M variables
- Added BDD-style acceptance criteria (Given/When/Then/And)
- Removed instructional bloat from templates (moved to instructions.md where it belongs)
- Template shows OUTPUT structure, instructions show PROCESS
- Applied to both create-epics-and-stories and tech-spec workflows
- Templates now use HTML comments to indicate repeating sections

### 5. Workflow.yaml Pattern Consistency
- Standardized input_file_patterns across all workflows
- Separated `recommended_inputs` (semantic WHAT) from `input_file_patterns` (file discovery WHERE)
- Removed duplication between recommended_inputs file paths and input_file_patterns
- Create-epics-and-stories now uses proper whole/sharded pattern like architecture workflow
- Solutioning-gate-check cleaned up to use semantic descriptions not file paths

## Files Changed (18)
- Core: workflow.xml (removed elicit-required tag and references)
- Audit workflow: Updated tag pattern scanner
- PRD workflow: Elicitation points, track migration, input discovery
- Create-epics-and-stories: Template rebuild, BDD format, elicitation, input patterns
- Tech-spec: Template rebuild, BDD format, input discovery
- UX Design: Input discovery streamlined
- Architecture: Elicitation at 5 key decision points, input discovery
- Gate-check: Input pattern cleanup, input discovery

## Impact
- More consistent elicitation across workflows
- Cleaner, more maintainable templates
- Better separation of concerns (templates vs instructions)
- Aligned with v6 3-track scale system
- Reduced bloat and duplication significantly

src/modules/bmm/workflows/2-plan-workflows/tech-spec/instructions.md

@@ -10,26 +10,8 @@
 <critical>Level 0: tech-spec + single user story | Level 1: tech-spec + epic/stories</critical>
 <critical>LIVING DOCUMENT: Write to tech-spec.md continuously as you discover - never wait until the end</critical>
 <critical>CONTEXT IS KING: Gather ALL available context before generating specs</critical>
-
 <critical>DOCUMENT OUTPUT: Technical, precise, definitive. Specific versions only. User skill level ({user_skill_level}) affects conversation style ONLY, not document content.</critical>
-
-## 📚 Input Document Discovery
-
-This workflow intelligently discovers and loads all available context including: product brief, research documents, brownfield project documentation, and project setup files.
-
-**Discovery Process** (execute for each referenced document):
-
-1. **Search for whole document first** - Use fuzzy file matching to find the complete document
-2. **Check for sharded version** - If whole document not found, look for `{doc-name}/index.md`
-3. **If sharded version found**:
-   - Read `index.md` to understand the document structure
-   - Read ALL section files listed in the index
-   - Treat the combined content as if it were a single document
-4. **Brownfield projects**: The `document-project` workflow always creates `{output_folder}/docs/index.md`
-
-**Priority**: If both whole and sharded versions exist, use the whole document.
-
-**Fuzzy matching**: Be flexible with document names - users may use variations in naming conventions.
+<critical>Input documents specified in workflow.yaml input_file_patterns - workflow engine handles fuzzy matching, whole vs sharded document discovery automatically</critical>
 
 <step n="0" goal="Validate workflow readiness and detect project level" tag="workflow-status">
 <action>Check if {output_folder}/bmm-workflow-status.yaml exists</action>