Capture and compare original source Display request geometry

[wieslawsoltes]

Scope

Adds independent original-Windows Typeface request-metric capture before TextFormatter/FormatLine, and a separate native source-double comparison probe over LayoutHintedSourceParagraph. Original 192-case and 288-case receipts, glyph order, assertions and 60-second/90-second/eight-minute bounds stay intact. New schemas 2/4 are separate CreateNew outputs; failure cannot erase prior primary observations. Exact internal diagnostic reflection is signature/assembly/face checked with no fallback.

Depends on #266 for the actual retained source producer and on #261 for the full original midpoint/Hebrew inventory. Both histories are preserved through normal merges. This draft is stacked on #266; dependencies must qualify/merge before retargeting to main.

The new source probe retains original doubles and full case/run/UTF-16/occurrence ownership, compares actual native source-run offsets/advances and line geometry without repair, and executes both explicit TT35/TT40 choices. All numeric policies are caller-selected. Old raw probe remains separate. Source-input allowlist now admits only the four exact schemas2/4 captured at92f4778b0 by successful original Windows workflow37011550318. Independent font/em/DPI/method/assembly identities were reviewed, all original case payloads exactly match prior immutable receipts, and cross-architecture input metrics agree. Old192/v3 schemas still cannot substitute missing metrics. No ordinary Display registration or parity claim.

Bounded postcommit checks

• New device-free parser/comparison controls: initial31/31 against each original x64/ARM64 192/288 receipt; after input qualification37/37 against each paired old/new schema1/2 and3/4 receipt (148 executions, zero skipped).
• Existing raw-probe64/64 and original midpoint17/17 controls pass unchanged.
• Original Windows reference project source compile: zero warnings/errors against cached references; no Windows execution.
• Six executable C# files parsed; YAML and all4 PowerShell blocks parsed without execution; git diff --check passed.
• Native-linked probe type build/execution awaits qualified coherent producer packages. No local native/renderer/full-source builds, GPU/VM execution or runtime staging.

Hosted original-Windows workflow37011550318 succeeded on both architectures with every original primary and independent input capture. New head35d0a5cce has reference workflow37012562360 queued; the capture implementation is unchanged by its parser/hash-only update. Complete exact successful native Build qualification is still required before any native comparison execution.

[wieslawsoltes]

Hosted probe type compilation passed at bc048af829aa8fa248008c9fdb254da4b26a3021 in Linux job110865946418, step11: actual Backend.Native/Text outputs, Release/linux-x64/CI, BuildProjectReferences=false, zero warnings/errors, 1.46seconds. No native probe execution or producer qualification is claimed.

The same job later failed only the existing Boolean vector-mask allocation fixture at sample grid4: 3,168bytes versus zero; grids1/8 passed. Suite result: 5,553passed, one failed, nine existing skips. The allocation origin is not established.

Head b6ef52b84007b43ae75aac87bbe5cddb02ff6487 now carries only the already-reviewed test isolation and receipt via cherry-pick -x from fb7e1fd2e/055d1b0c9; no #264 shader feature ancestry. The helper, original payload, one warmup, 10,000 calls, exact-zero threshold, positive controls and validation match the reviewed files byte-for-byte; the new compile gate is unchanged. No redundant local graph/native validation or runtime staging occurred.

Replacement whole Build37019061789 is confirmed at the new exact head. The superseded failed run is not qualified. The independent source-policy comparison still awaits whole-successful producer #266 and will initially run only its explicit actual source-policy triple against all four reviewed input receipts, preserving both TT35/40 and every rejected/unmatched observation.