feat: add application validation command

Add /validate-application slash command to ensure application.md files
are complete before document generation. Validates required sections
(Organization Info, Job Info, Job Description), detects placeholders
like [To be filled], warns if input/ folder is empty, and provides
structured pass/fail output consistent with /validate-profile.

This acts as a quality gate in the application workflow, preventing
placeholder text from appearing in generated documents.

OpenSpec: add-application-validation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/CLAUDE.md

@@ -187,14 +187,21 @@ When helping with job applications, follow this comprehensive workflow:
 - Adjust which experiences and projects to emphasize
 - Fine-tune key messages and tone
 
-### 5. Content Generation (FUTURE)
+### 5. Validate Application (NEW - Quality Gate)
+- Run `/validate-application` to ensure application.md is complete
+- Check that required sections are filled (Organization, Job Title, Job Description)
+- Verify no placeholder text remains (like `[To be filled]`)
+- Get warnings if input/ folder is empty or application seems unpopulated
+- **Must pass before document generation**
+
+### 6. Content Generation (FUTURE)
 - Generate CV/cover letter/email based on `application.md` strategy
 - Emphasize relevant experience from `profile.md`
 - Incorporate keywords from the job description naturally
 - Maintain factual accuracy - use only verified information from `profile.md`
 - **Note**: Document generation will be implemented in a future update
 
-### 6. Quality Assurance
+### 7. Quality Assurance
 - Verify all company names, dates, and facts are correct
 - Ensure consistency between all documents (CV ↔ cover letter ↔ email)
 - Check that tone matches the target company culture
@@ -255,6 +262,7 @@ Adjust recommendations based on the target market if the user specifies a differ
 - `/validate-profile` - Validate that `profile.md` is complete and ready for application generation
 - `/new-application "Company - Job Title"` - Create a new application workspace with organized folder structure
 - `/populate-application` - Analyze input documents and populate application.md with job info, research, and strategy
+- `/validate-application [optional-app-name]` - Validate that application.md is complete before document generation
 
 ## Example Usage
 
@@ -268,7 +276,9 @@ Adjust recommendations based on the target market if the user specifies a differ
 3. After application is created, guide user: "Add the job posting and any other documents to `applications/pending/[folder]/input/`"
 4. When user has added documents: "Navigate to the application folder and run `/populate-application`"
 5. After population completes: "Review `application.md` to see the analysis and strategy"
-6. Future: Generate tailored CV, cover letter, and email based on `application.md`
+6. Validation step: "Run `/validate-application` to ensure the application is complete"
+7. If validation passes: Ready for document generation
+8. Future: Generate tailored CV, cover letter, and email based on `application.md`
 
 ### Example 2: Quick Document Request (Legacy Flow)
 
@@ -283,6 +293,17 @@ Adjust recommendations based on the target market if the user specifies a differ
 6. Generate tailored cover letter using only information from `profile.md`
 7. Suggest: "For better organization, consider using `/new-application` next time to manage the full application process"
 
+### Example 3: Validating an Application
+
+**User**: "Check if my TechCorp application is ready"
+
+**Claude Code should**:
+1. If user is in application folder: Run `/validate-application` (auto-detects current location)
+2. If user is elsewhere: Run `/validate-application 2025-11-02-TechCorp-Software-Engineer`
+3. If validation passes (✅): "Your application is complete! Organization: TechCorp, Position: Software Engineer. Ready for document generation."
+4. If validation fails (❌): Show specific issues like "Organization Name: Contains placeholder '[To be filled]'" and suggest "Please update application.md or run `/populate-application` if you have documents in input/"
+5. Provide clear next steps based on validation result
+
 ## Updating the Profile
 
 If you notice missing or outdated information during application preparation: