fix(protobuf): reject malformed varints across values and framing

[samchon]

Closes #2256.

A malformed Protocol Buffer varint could become success-shaped decoded output. All value and framing consumers share the tenth wire byte, so the fix enforces its single legal payload bit in one reader boundary in _ProtobufReader.ts, and corrects the #2139 reader regression that had frozen ten-continuation acceptance.

Verification

Independently verified by an agent that did not write the implementation and built its own oracle rather than reusing the batch's test material.

Measure	Result
Differential vs official protowire v1.34.2 — 885 byte strings x 8 reader entry points	7080/7080 cells agree, 0 disagreements
Same differential on the base commit	3971 disagreeing cells over 530 inputs, every one accepts-illegal
Regressions / loosened cells introduced	0 / 0
Oracle-accepted inputs decoding to the exact value at the exact consumed length	208 / 208
Exhaustive tenth-byte partition, both prefix families	accepts exactly {0x00, 0x01}, bit-identical to the oracle; base accepted all 256
Cross-reader consistency among the 8 consumers	0 disagreements, against 269 on base
Public wrapper matrix (direct/factory x raw/assert/is/validate)	152/152 threw a prefixed Error — never null, never success: false

Mutation proof: reverting only _ProtobufReader.ts fails exactly the three coupled regressions while all fifteen adjacent protobuf controls pass. Gates at the head: pnpm build, 18 protobuf cases, 178-case test-typia-schema, feature identity, go vet in both trees, and tagged native ../native/... (28 packages, 0 failures).

The changed #2139 expectation is a correction, not a laundered regression

A previously merged test asserted that typia must accept 0x80 x10, 0x01 as 0. protowire rejects that input with n = -3. The old expectation was wrong; the new one matches both the wire specification and the oracle. Adjudicated independently against the specification rather than against this pull request's narrative.

Second commit: the oracle test could not fail

Independent verification found the first commit's permanent TestProtobufVarintBoundsOracle passed with the product fix fully reverted — it exercised protowire alone, never called typia, and its agreement with the TypeScript regressions was hand transcription. A permanent test that cannot fail when the work regresses is a false green, so the batch was returned for a test-asset remediation.

Every byte string and verdict now lives in one packages/typia/test/protobuf_varint_corpus.json that the Go test and both TypeScript regressions read. The Go test is renamed to state that it pins the official parser's verdicts only. Verified by mutating the corpus seven ways — value, consumed length, fault relabelling, emptied entries, unknown class, a fabricated contradictory row, and an accepted/rejected flip — with both halves reacting to every mutation.

The same commit splits one error message that had described two different faults: a continuing tenth byte keeps varint exceeds 10 bytes., while a terminating tenth byte carrying payload above bit 0 now reports varint exceeds 64 bits. Acceptance is byte-identical — proven by re-running the full 7080-cell differential across both heads: 0 acceptance differences, 0 value differences, 2088 message-only differences. No website page, documentation, example, or tracked test outside this batch pinned the old string.

Out of scope, recorded for the next discovery round

Two verified, user-visible defects present identically on the base commit and on this fix, outside this issue's published invariant: length prefixes and field tags are silently truncated to 32 bits, so a field declaring 4,294,967,301 bytes reads five, and field 536870913 aliases onto field 1. A third consumer of the same truncation, bool(), decodes from the low 32 bits only. None is locked in by the new tests, so the next round can decide the contract rather than inherit a snapshot.

Campaign constraints

No package version, tag, release, publication, or packages/interface/src change. pnpm format was not run.