Detect weak types in predicates and mapped keys

[rogerchappel]

Summary

• propagate nested any and unknown through type predicates, including asserts predicates
• inspect mapped-type constraints, remapped key types, and value annotations with existing any-over-unknown precedence
• add parser and CLI fixtures plus document the supported traversal

Commits

• 50518b5 test: cover nested weak predicate and mapped types
• d25f49b fix: traverse predicate and mapped type components
• 6bf4a2d docs: define nested weak type propagation

Verification

• npm ci --ignore-scripts --no-audit --no-fund
• npm run release:check (138 tests; typecheck, lint, build, smoke, validation, package smoke, audits)
• git diff --check origin/main...HEAD
• author and committer identity verified for every commit as Roger Chappel <miscanalysis@gmail.com>

[rogerchappel]

Automated merge note

Triage class: auto-merge

Summary: Extends nested weak-type detection to TypeScript predicates and all mapped-type components, with focused parser/CLI regressions and user documentation (5 files, +59/-3).

Checks run: GitHub CI test (Node 20.19.0), test (Node 22), and test (Node 24) — all COMPLETED/SUCCESS; originating worker ran npm ci --ignore-scripts --no-audit --no-fund, npm run release:check (138 tests, audits, typecheck, lint, build, smoke, validation, package smoke), and git diff --check. Final full diff (SHA-256 27ef24b9208c1680da18ce1dcaeb79e779a2e63655fd656593b32e7500766704), mergeability, one-review branch protection, and exact Roger Chappel author/committer identities re-verified.

Rebased/CI-repaired: No.

Verified head SHA: 6bf4a2d.