release: promote FrameVitals 0.3.0 stabilization to dev

[parthdongre]

Summary

Promotes the long-lived develop/august stabilization work into dev as the first 0.3.0 release-candidate integration step.

This includes:

• configurable per-run execution resource policies and deterministic environment/config precedence;
• versioned dependency-aware planning and reusable AnalysisContext state;
• hard-cap correctness for materialized and streaming quality diagnostics;
• snapshot integrity validation and monitoring fixes;
• web, upload, CSV, RAG, AI fallback, safe-pandas, frontend HTTP, and deployment-route hardening;
• compatibility fixes and release documentation updates already accumulated on the stabilization branch.

The target dev branch also retains its three frontend dependency commits, so this PR intentionally integrates both lines instead of bypassing dev.

Release gate

The current stabilization head is green on core Python 3.11/3.12/3.13, Python 3.11 lower bounds, Arrow fallback, frontend build, package quality, and native Rust/Python bridge checks. Additional PR checks should validate the combined dev state.

develop/august should remain after merge; it is a long-lived development branch.