fix: resolve GitHub issues (#50, #54)

- #54: Add API endpoint configuration documentation to DASHBOARD_GUIDE.md
- #50: Add brainstorm context overflow protection with output size limits

Note: #72 and #53 not changed per user feedback - existing behavior is sufficient
(users can configure envFile themselves; default Python version is appropriate)

.claude/agents/conceptual-planning-agent.md

@@ -308,3 +308,37 @@ When analysis is complete, ensure:
 - **Relevance**: Directly addresses user's specified requirements
 - **Actionability**: Provides concrete next steps and recommendations
 
+## Output Size Limits (Context Overflow Prevention)
+
+**⚠️ CRITICAL**: To prevent API context overflow in brainstorm workflows, enforce these limits:
+
+### Document Size Limits
+- `analysis.md` (main): **< 3000 words** (~12KB)
+- `analysis-*.md` (sub-docs): **< 2000 words each** (~8KB)
+- Maximum 5 sub-documents per role
+- **Total per-role**: **< 15000 words** (~60KB)
+
+### Strategies for Staying Within Limits
+1. **Be concise**: Focus on key insights, not exhaustive detail
+2. **Use bullet points**: More efficient than prose paragraphs
+3. **Reference don't repeat**: Use `@filename.md` references instead of duplicating content
+4. **Prioritize**: Include top 3-5 recommendations per section, not all possible ones
+5. **Defer details**: Mark "further analysis needed" for complex areas instead of expanding
+
+### Self-Check Before Output
+```
+Before writing files, verify:
+□ Main analysis.md < 3000 words
+□ Each sub-document < 2000 words
+□ Total sub-documents ≤ 5
+□ No duplicated content across files
+□ References used where appropriate
+```
+
+### If Limit Exceeded
+If analysis naturally exceeds limits:
+1. Split into essential vs nice-to-have content
+2. Move nice-to-have to a separate `analysis-appendix.md` (counts toward 5 sub-doc limit)
+3. Use executive summary style for main document
+4. Note "detailed analysis available on request" for deferred topics
+