Support Direct2D source copies into clipped compatible targets

[wieslawsoltes]

Scoped functionality

Adds CopyFromBitmap and CopyFromRenderTarget into compatible targets with active aliased axis-aligned destination clips. The shared builder suspends and restores those exact clip scopes around the existing immutable SRC copy transaction. Full replacement retains captured drawing scopes; partial writes retain history.

This draft is stacked on #273 (feat/direct2d-scoped-memory-copy), exact dependency 4d159e87b6866f510c56abb512e32760d08cfb21. That dependency is not yet qualified. No automatic issue closure or general Direct2D compatibility claim is intended.

Source active clips/layers and scoped self-copies remain rejected. Snapshot capture precedes destination locking; format, alpha, independent DPI, physical crop, original source errors and caller state remain authoritative. No source COM identity is retained, and no renderer fallback, C ABI/COM slot/wire change or default alteration is introduced.

Tests and qualification boundary

• Eight new source-copy pixel sequences cover both methods, full/partial overwrite, 96/192 destination DPI, nonuniform source DPI, nonzero crop, transparent replacement, source mutation/disposal and following clipped draws.
• Both providers retain exact cold/warm/independent pixels and submission counts; the original Windows Direct2D/WIC lane independently executes all eight sequences. All four existing memory-copy cases remain.
• Twelve portable rejection cases, moved-resource byte-exact rollback controls and an additive named-module consumer are authored.
• Post-commit strict C++20 syntax checks passed for the actual shared image builder, Direct2D target, builder tests, compatibility tests and instantiated pixel fixtures, with 45-second process bounds. Memory inventory and diff checks passed.

No local native binary was built or executed; no GPU, VM, runtime staging or Windows observation ran locally. Hosted full Build, both-provider pixels, original Windows controls and application qualification remain required. Syntax checks are not behavioral qualification.

Implementation provenance and Microsoft contract links are recorded in docs/direct2d-scoped-source-copies.md.