feat(extension): idstack Chrome Extension with Canvas Course Crawler & BYOK

[savvides]

Summary

Brings idstack's evidence-based course design audits to educators and instructional designers outside the terminal via a native Manifest V3 Chrome Side Panel.

Key Capabilities

• Full Canvas Course Crawler: Automatically navigates and aggregates published syllabus content, assignments, and rubrics in the background using the user's active Canvas session (zero IT admin setup or developer tokens required).
• Single-Page & Whole-Course Audits: Classifies Bloom's Revised Taxonomy levels, evaluates constructive alignment across entire module roadmaps, and suggests research-grounded fixes.
• T1–T5 Research Badges: Findings cite the 108 peer-reviewed empirical studies in evidence/references.md.
• Free Google AI Studio Onboarding & Demo Simulation: Instant testability with built-in demo simulations plus direct link to get a free Google AI Studio API key.
• Scholarly Publication Aesthetic: Follows DESIGN.md publication tokens with 1-click clipboard actions and sanitized HTML rendering.
• Verification: All 7 extension test suites and 356 master smoke checks passing.