- ambientUndefVarRootOf walks calls, `new`, optional chains, assertions, instantiation expressions, and tagged templates, and accepts `declare function` and trap-binding roots: Node erases the declaration, so the root read IS the crash — lowerCall, member reads, assignments, and variable declarations lower the whole statement to the catchable ReferenceError, arguments never evaluate, and the never-initialized binding registers as a trap whose references can never run
- never-read unmappable bindings with value-only initializers and writes emit nothing: Node builds the value and drops it, so `var xs2: typeof Array;` and the write-only `var f2: { <T, U>(x: T, y: U): T }` compile instead of fencing on a type the program never consumes
- null!/as-any bindings whose types keep generic signatures (or intern empty record shapes) register no storage; generic-method calls and member reads through them compile to Node's exact TypeError, nullish-to-nullish flows to nothing, heritage-clause uses decline the family so mixin resolution keeps its fence, and checked-dynamic (`any`) bindings keep their dyn story untouched
- assertion-shaped generic arrows (`< <T>(x: T) => T >((x) => x)`) register like annotated bindings and monomorphize per call; stdlib generic members (Promise.then, Object.defineProperty) take the SC2020 lib fence, and Function.prototype.apply/call/bind on compiled function values name the direct-call spelling
- diagnostics fixtures that used `declare` to conjure unconstructible values now conjure them by cast so each fence family keeps its pin; snapshots re-recorded, the deferred checker-panic diagnostic now flushes at its first reference as designed
- New codes, minted in badType's classification order: SC2005 values whose type keeps a generic call signature, SC2006 index-signature shapes outside the supported set, SC2007 overloaded function types, SC2008 intersections with no resolved lowering, SC2009 supported container/function/record shapes over a component outside its slot — the SC2009 message names the offending component (Map/Set key-value domains, array/tuple elements, union arms, function rest/params/returns, record members) via describeComponentBlocker/describeRecordMemberBlocker in frontend/types.ts, which mirror mapType's own rules on the failure path only.
- Standard-library nominal types with no lowering at all (Date, ArrayBuffer, WeakMap, the iterator and constructor interfaces) now route to the existing SC2020 story instead of the supported-set recitation; stdlib provenance is checked after the container claims so Map/Set/Promise instantiation failures keep their component story.
- SC2001 keeps the honest remainder — bigint and symbol primitives, constructor objects, and library-derived or unresolved generic shapes — and its registry name now says so; across the diagnostics corpus its rendered sites drop from 57 to 5.
- Every new code flows through the diagnostics registry, the regenerated surface manifest, and coverage-report grouping; five new tests/diagnostics programs pin one rendered frame per code, and the ts7 order-parity baselines re-record to include them.
- Zero behavior change to accepted programs: the differential corpus (900 programs) is untouched and green, and the full suite passes.
