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>

config/schemas/__init__.py

@@ -0,0 +1,47 @@
+"""
+CXInsights - Schema Definitions
+
+Export all schema models from the current version.
+"""
+
+from config.schemas.call_analysis_v1 import (
+    SCHEMA_VERSION,
+    BatchManifest,
+    CallAnalysis,
+    CallOutcome,
+    CompressedTranscript,
+    DataSource,
+    Event,
+    EventType,
+    EvidenceSpan,
+    FailureReason,
+    ObservedFeatures,
+    ProcessingStatus,
+    RCALabel,
+    SpeakerTurn,
+    Traceability,
+    Transcript,
+    TranscriptMetadata,
+    TurnMetrics,
+)
+
+__all__ = [
+    "SCHEMA_VERSION",
+    "DataSource",
+    "ProcessingStatus",
+    "FailureReason",
+    "EventType",
+    "CallOutcome",
+    "Traceability",
+    "SpeakerTurn",
+    "TranscriptMetadata",
+    "Transcript",
+    "Event",
+    "TurnMetrics",
+    "ObservedFeatures",
+    "EvidenceSpan",
+    "RCALabel",
+    "CallAnalysis",
+    "CompressedTranscript",
+    "BatchManifest",
+]