feat(parser): emit FUNCTION nodes for namespace-assigned JS functions

[smochan]

Summary

Plain-script JS (no ES modules) attaches its API to namespace objects — CGUI.esc = function esc(s) {...}, window.CGViews.flows = (host) => {...}. The parser handled function declarations and const-assigned functions but emitted nothing for member-expression assignments, leaving these functions invisible to the graph.

Concrete impact: PR #73's helper move (app.js → ui/helpers.js, the new module pattern of the whole refactored dashboard) was flagged removed-referenced critical three times, because the new CGUI.* definitions produced no added nodes for the move detection (#76) to match.

New _handle_assigned_function in the module-level visitor:

• LHS must be a member expression of plain identifiers (computed members obj[key] skipped)
• window. prefix stripped (environment artifact, not a namespace)
• node name = property name (the API name callers use); inner named function expressions preserved as metadata.function_name
• body calls/fetches attributed to the new node like every other handler

Test plan

• 3 new extractor tests + fixture (assignment forms, skip rules, CALLS attribution)
• Full suite: 779 passed
• ruff + mypy --strict clean
• codegraph lint self-run clean

Unblocks #73 (final wave-2 train car).

🤖 Generated with Claude Code

[github-actions]

codegraph PR review

Diff vs main · severity ≤ high

codegraph review (target: main)

Diff: +9 / -0 / ~0 nodes, +239 / -164 edges

Findings (0)

No findings.

_{Triggered by codegraph CI · last run}