fix: correct embedded file paths to use _bmad/bmm instead of src/bmm

Paths in workflow step files reference `{project-root}/src/bmm/...` which
works in the source repository but breaks when installed to a project
(where the path should be `{project-root}/_bmad/bmm/...`).

Files fixed:
- PRD workflow steps (step-e-01, step-e-01b, step-e-02, step-e-03)
- Test design workflow (tea-index.csv references)

Fixes #1436

src/bmm/workflows/2-plan-workflows/create-prd/steps-e/step-e-01-discovery.md

@@ -4,7 +4,7 @@ description: 'Discovery & Understanding - Understand what user wants to edit and
 
 # File references (ONLY variables used in this step)
 altStepFile: './step-e-01b-legacy-conversion.md'
-prdPurpose: '{project-root}/src/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
+prdPurpose: '{project-root}/_bmad/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
 advancedElicitationTask: '{project-root}/_bmad/core/workflows/advanced-elicitation/workflow.xml'
 partyModeWorkflow: '{project-root}/_bmad/core/workflows/party-mode/workflow.md'
 ---

src/bmm/workflows/2-plan-workflows/create-prd/steps-e/step-e-01b-legacy-conversion.md

@@ -5,7 +5,7 @@ description: 'Legacy PRD Conversion Assessment - Analyze legacy PRD and propose
 # File references (ONLY variables used in this step)
 nextStepFile: './step-e-02-review.md'
 prdFile: '{prd_file_path}'
-prdPurpose: '{project-root}/src/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
+prdPurpose: '{project-root}/_bmad/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
 ---
 
 # Step E-1B: Legacy PRD Conversion Assessment

src/bmm/workflows/2-plan-workflows/create-prd/steps-e/step-e-02-review.md

@@ -6,7 +6,7 @@ description: 'Deep Review & Analysis - Thoroughly review existing PRD and prepar
 nextStepFile: './step-e-03-edit.md'
 prdFile: '{prd_file_path}'
 validationReport: '{validation_report_path}'  # If provided
-prdPurpose: '{project-root}/src/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
+prdPurpose: '{project-root}/_bmad/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
 advancedElicitationTask: '{project-root}/_bmad/core/workflows/advanced-elicitation/workflow.xml'
 ---
 

src/bmm/workflows/2-plan-workflows/create-prd/steps-e/step-e-03-edit.md

@@ -5,7 +5,7 @@ description: 'Edit & Update - Apply changes to PRD following approved change pla
 # File references (ONLY variables used in this step)
 nextStepFile: './step-e-04-complete.md'
 prdFile: '{prd_file_path}'
-prdPurpose: '{project-root}/src/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
+prdPurpose: '{project-root}/_bmad/bmm/workflows/2-plan-workflows/create-prd/data/prd-purpose.md'
 ---
 
 # Step E-3: Edit & Update

src/bmm/workflows/testarch/test-design/instructions.md

@@ -105,7 +105,7 @@ TEA test-design workflow supports TWO modes, detected automatically:
 
 3. **Load Knowledge Base Fragments (System-Level)**
 
-   **Critical:** Consult `src/bmm/testarch/tea-index.csv` to load:
+   **Critical:** Consult `{project-root}/_bmad/bmm/testarch/tea-index.csv` to load:
    - `adr-quality-readiness-checklist.md` - 8-category 29-criteria NFR framework (testability, security, scalability, DR, QoS, deployability, etc.)
    - `test-levels-framework.md` - Test levels strategy guidance
    - `risk-governance.md` - Testability risk identification
@@ -139,7 +139,7 @@ TEA test-design workflow supports TWO modes, detected automatically:
 
 4. **Load Knowledge Base Fragments (Epic-Level)**
 
-   **Critical:** Consult `src/bmm/testarch/tea-index.csv` to load:
+   **Critical:** Consult `{project-root}/_bmad/bmm/testarch/tea-index.csv` to load:
    - `risk-governance.md` - Risk classification framework (6 categories: TECH, SEC, PERF, DATA, BUS, OPS), automated scoring, gate decision engine, owner tracking (625 lines, 4 examples)
    - `probability-impact.md` - Risk scoring methodology (probability × impact matrix, automated classification, dynamic re-assessment, gate integration, 604 lines, 4 examples)
    - `test-levels-framework.md` - Test level selection guidance (E2E vs API vs Component vs Unit with decision matrix, characteristics, when to use each, 467 lines, 4 examples)