Extract app.js monolith (4,707 lines) into modules

[sgardoll]

Summary

app.js contains all application logic in a single 4,707-line file: encryption, API key management, 4 API clients, FlutterFlow API client class, pubspec/YAML handling, commit orchestration, 3 pipeline functions, markdown rendering, UI orchestration, initialization, and feedback.

Risk Assessment

• Risk Level: High
• Likelihood: Certain — impacts every development session
• Impact: Growing — each feature addition increases risk
• Timeline: Accumulating now, rewrite pressure within 12 months

Current State

A src/ directory exists with ffState/, fileUtils/, types/ subdirectories — suggesting a module split was started but never completed.

Impact Trajectory

• Today: Cognitive overload, long git diffs, merge conflicts
• 6 months: Fear of touching code — changes cascade unpredictably
• 12 months: Rewrite pressure because patching becomes too risky

Suggested Incremental Extraction

Start with pure-logic functions (no DOM dependencies):

Module	Lines	Dependencies
crypto.js	218-362	None (Web Crypto API)
pubspec.js	~1700-2800	None (pure data)
markdown-renderer.js	3270-3450	highlight.js
flutterflow-client.js	1250-1459	None (fetch)
api-clients.js	992-1230	Global API keys
pipeline.js	2806-3260	API clients
ui.js	Remaining DOM code	Everything above

Each extraction should:

1. Move the code to a new ES module file
2. Export the public API
3. Import in app.js (preserving behavior)
4. Verify no regressions