feat: Add Streamlit dashboard with Blueprint compliance (v2.1.0)

Dashboard Features:
- 8 navigation sections: Overview, Outcomes, Poor CX, FCR, Churn, Agent, Call Explorer, Export
- Beyond Brand Identity styling (colors #6D84E3, Outfit font)
- RCA Sankey diagram (Driver → Outcome → Churn Risk flow)
- Correlation heatmaps (driver co-occurrence, driver-outcome)
- Outcome Deep Dive (root causes, correlation, duration analysis)
- Export functionality (Excel, HTML, JSON)

Blueprint Compliance:
- FCR: 4 categories (Primera Llamada/Rellamada × Sin/Con Riesgo de Fuga)
- Churn: Binary view (Sin Riesgo de Fuga / En Riesgo de Fuga)
- Agent: Talento Para Replicar / Oportunidades de Mejora
- Fixed FCR rate calculation (only FIRST_CALL counts as success)

Technical:
- Streamlit + Plotly for interactive visualizations
- Light theme configuration (.streamlit/config.toml)
- Fixed Plotly colorbar titlefont deprecation

Documentation:
- Updated PROJECT_CONTEXT.md, TODO.md, CHANGELOG.md
- Added 4 new technical decisions (TD-014 to TD-017)
- Created TROUBLESHOOTING.md with 10 common issues

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,132 @@
+# ============================================
+# CXInsights .gitignore
+# ============================================
+
+# === Environment & Secrets ===
+.env
+.env.local
+.env.*.local
+*.pem
+*.key
+secrets/
+
+# === Data (CRITICAL - never commit) ===
+data/raw/
+data/transcripts/
+data/features/
+data/processed/
+data/outputs/
+data/output/
+data/logs/
+data/.checkpoints/
+data/examples/*.json
+!data/**/.gitkeep
+
+# === Python ===
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# === Virtual Environment ===
+.venv/
+venv/
+ENV/
+env/
+.python-version
+
+# === IDE & Editors ===
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+.project
+.pydevproject
+.settings/
+*.sublime-workspace
+*.sublime-project
+
+# === Jupyter Notebooks ===
+.ipynb_checkpoints/
+*.ipynb_checkpoints/
+
+# === Testing ===
+.coverage
+.pytest_cache/
+htmlcov/
+.tox/
+.nox/
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+
+# === Mypy ===
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# === Ruff ===
+.ruff_cache/
+
+# === OS Files ===
+.DS_Store
+Thumbs.db
+ehthumbs.db
+Desktop.ini
+
+# === Logs ===
+*.log
+logs/
+log/
+
+# === Build Artifacts ===
+*.exe
+*.dll
+*.dylib
+
+# === Temporary Files ===
+*.tmp
+*.temp
+*.bak
+*.backup
+tmp/
+temp/
+
+# === Claude Code ===
+.claude/
+
+# === Model Outputs (large files) ===
+*.pdf
+*.xlsx
+*.png
+*.svg
+!docs/**/*.png
+!docs/**/*.svg
+
+# === Audio Files (CRITICAL - never commit) ===
+*.mp3
+*.wav
+*.m4a
+*.flac
+*.ogg
+*.aac
+!tests/fixtures/sample_audio/*.mp3