Dev Log v0.9.2 - Guardrails + UI Standardization + Dev Analytics Tooling

Added guardrail scripts to protect marketing/training boundaries, standardized UI imports, and expanded dev-only analytics + accessibility tooling.

Shipped

Added guardrail scripts:
- check-marketing-untouched.mjs to protect marketing surfaces
- check-training-legacy-classes.mjs to prevent reintroducing legacy training CSS drift
Standardized Button imports across the app for consistency (@/components/ui/button)
Enhanced training styling foundations:
- Training-specific tokens imported via globals.css
- Added training-local UI primitives (Button/Card/Dialog) for cleaner consistency
- Improved training layout/sidebar and added theme toggle support
Expanded dev instrumentation tooling:
- Dev-only Analytics Debug Panel for inspecting recent events/payloads
- Dashboards-as-code sync for PostHog (JSON-driven create/update)
Continued accessibility improvements across dialogs and forms
Added/updated documentation for styling boundaries and design system conventions

Guardrails keep the codebase coherent as UI systems evolve (and prevent accidental regressions)
Standardized imports reduce component drift and styling inconsistencies
Dev-only analytics tools speed up iteration without shipping internal dashboards or exposing sensitive data