fix(workflows): improve monorepo context handling and sanitization

- Re-derive dependent paths in retrospective workflow after monorepo override
- Add max length validation for project_suffix in dev-story
- Fix premature output path computation in create-story workflow

src/bmm/workflows/4-implementation/create-story/instructions.xml

@@ -31,8 +31,7 @@
          <action>HALT</action>
       </check>
       <action>Override output_folder to {project-root}/_bmad-output/{project_suffix}</action>
-      <action>Set {default_output_file} = {output_folder}/{story_key}.md</action>
-      <action>Output "Monorepo context detected. Output redirected to: {default_output_file}"</action>
+      <action>Output "Monorepo context detected. Output folder redirected to: {output_folder}"</action>
     </check>
 
     <check if="{{story_path}} is provided by user or user provided the epic and story number such as 2-4 or 1.6 or epic 1 story 5">
@@ -277,48 +276,52 @@
   <step n="5" goal="Create comprehensive story file">
     <critical>📝 CREATE ULTIMATE STORY FILE - The developer's master implementation guide!</critical>
 
+    <!-- Recompute output file path with correct output_folder and story_key -->
+    <action>Set {target_story_file} = {output_folder}/{story_key}.md</action>
+    <action>Output "Generating story file at: {target_story_file}"</action>
+
     <action>Initialize from template.md:
-    {default_output_file}</action>
-    <template-output file="{default_output_file}">story_header</template-output>
+    {target_story_file}</action>
+    <template-output file="{target_story_file}">story_header</template-output>
 
     <!-- Story foundation from epics analysis -->
     <template-output
-      file="{default_output_file}">story_requirements</template-output>
+      file="{target_story_file}">story_requirements</template-output>
 
     <!-- Developer context section - MOST IMPORTANT PART -->
-    <template-output file="{default_output_file}">
-    developer_context_section</template-output> **DEV AGENT GUARDRAILS:** <template-output file="{default_output_file}">
+    <template-output file="{target_story_file}">
+    developer_context_section</template-output> **DEV AGENT GUARDRAILS:** <template-output file="{target_story_file}">
     technical_requirements</template-output>
-    <template-output file="{default_output_file}">architecture_compliance</template-output>
+    <template-output file="{target_story_file}">architecture_compliance</template-output>
     <template-output
-      file="{default_output_file}">library_framework_requirements</template-output>
-    <template-output file="{default_output_file}">
+      file="{target_story_file}">library_framework_requirements</template-output>
+    <template-output file="{target_story_file}">
     file_structure_requirements</template-output>
-    <template-output file="{default_output_file}">testing_requirements</template-output>
+    <template-output file="{target_story_file}">testing_requirements</template-output>
 
     <!-- Previous story intelligence -->
     <check
       if="previous story learnings available">
-      <template-output file="{default_output_file}">previous_story_intelligence</template-output>
+      <template-output file="{target_story_file}">previous_story_intelligence</template-output>
     </check>
 
     <!-- Git intelligence -->
     <check
       if="git analysis completed">
-      <template-output file="{default_output_file}">git_intelligence_summary</template-output>
+      <template-output file="{target_story_file}">git_intelligence_summary</template-output>
     </check>
 
     <!-- Latest technical specifics -->
     <check if="web research completed">
-      <template-output file="{default_output_file}">latest_tech_information</template-output>
+      <template-output file="{target_story_file}">latest_tech_information</template-output>
     </check>
 
     <!-- Project context reference -->
     <template-output
-      file="{default_output_file}">project_context_reference</template-output>
+      file="{target_story_file}">project_context_reference</template-output>
 
     <!-- Final status update -->
-    <template-output file="{default_output_file}">
+    <template-output file="{target_story_file}">
     story_completion_status</template-output>
 
     <!-- CRITICAL: Set status to ready-for-dev -->

src/bmm/workflows/4-implementation/dev-story/instructions.xml

@@ -25,6 +25,10 @@
          <output>🚫 Error: Project context must only contain alphanumeric characters, dots, dashes, or underscores.</output>
          <action>HALT</action>
       </check>
+      <check if="project_suffix.length > 100">
+         <output>🚫 Error: Project context name is too long (max 100 characters).</output>
+         <action>HALT</action>
+      </check>
       <action>Override output_folder to {project-root}/_bmad-output/{project_suffix}</action>
     </check>
 

src/bmm/workflows/4-implementation/retrospective/instructions.md

@@ -11,6 +11,9 @@ Load and read full config from {main_config} and resolve basic variables.
 1. Check if `{project-root}/_bmad/.current_project` exists.
 2. If it exists, read its content as `{project_suffix}` and override output folder:
    - `output_folder`: `{project-root}/_bmad-output/{project_suffix}`
+3. Re-derive dependent path variables to reflect the new `output_folder`:
+   - `implementation_artifacts`: `{output_folder}/implementation`
+   - `planning_artifacts`: `{output_folder}/planning`
 
 <critical>Communicate all responses in {communication_language} and language MUST be tailored to {user_skill_level}</critical>
 <critical>Generate all documents in {document_output_language}</critical>