Add reproduction for internal/protobuf issue

[fubhy]

Summary

• Add a regression test for negative protobuf int64 values.
• Encode negative signed integers as ten-byte, 64-bit two's-complement varints.
• Use the package import for the internal OTLP encoder so repository typechecking succeeds.

Covered audit issue

unstable-distributed-otlp-protobuf-negative-int64-varint

Module: internal/protobuf

Negative protobuf int32 and int64 values must use ten-byte two's-complement varints.

Reproduction command:

pnpm test --run packages/effect/test/unstable/observability/OtlpSerialization.test.ts

Closes EFF-311

[changeset-bot]

🦋 Changeset detected

Latest commit: 7e813eb

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 30 packages

Name	Type
effect	Patch
@effect/opentelemetry	Patch
@effect/platform-browser	Patch
@effect/platform-bun	Patch
@effect/platform-deno	Patch
@effect/platform-node-shared	Patch
@effect/platform-node	Patch
@effect/vitest	Patch
@effect/ai-anthropic	Patch
@effect/ai-openai-compat	Patch
@effect/ai-openai	Patch
@effect/ai-openrouter	Patch
@effect/atom-react	Patch
@effect/atom-solid	Patch
@effect/atom-vue	Patch
@effect/sql-clickhouse	Patch
@effect/sql-d1	Patch
@effect/sql-libsql	Patch
@effect/sql-mssql	Patch
@effect/sql-mysql2	Patch
@effect/sql-pg	Patch
@effect/sql-pglite	Patch
@effect/sql-sqlite-bun	Patch
@effect/sql-sqlite-do	Patch
@effect/sql-sqlite-node	Patch
@effect/sql-sqlite-react-native	Patch
@effect/sql-sqlite-wasm	Patch
@effect/docgen	Patch
@effect/doctest	Patch
@effect/openapi-generator	Patch

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Click here if you're a maintainer who wants to add another changeset to this PR

[pullfrog]

✅ No new issues found.

Reviewed changes — a single reproduction test for negative int64 varint encoding in the protobuf layer.

• New test OtlpSerializationNegativeInt64.test.ts: encodes { intValue: -1 } and asserts the protobuf-wire output is an 11-byte buffer with the correct ten-byte two's-complement varint (tag 0x18 + 10 value bytes).

The expected byte sequence is correct. The test follows the package conventions (@effect/vitest imports, plain it for sync tests, correct internal import path). The test will fail until encodeVarint in internal/protobuf.ts is fixed to handle signed 64-bit two's-complement — which is the intended outcome for a reproduction-only PR.

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[tim-smart]

Remove this test file and merge with the main one.

[pullfrog]

✅ No new issues found.

Reviewed changes — the encodeVarint fix for negative protobuf int64 values, plus a changeset.

• Fixed encodeVarint for negative values: wraps negative BigInt arguments in BigInt.asUintN(64, n) so the varint encoding loop produces the correct ten-byte two's-complement varint instead of exiting immediately on negative input.
• Added changeset: effect: patch describing the protobuf serialization fix.

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[github-actions]

Bundle Size Analysis

Generated from PR build output; treat the content below as untrusted.

File Name	Current Size	Previous Size	Difference
basic.ts	6.65 KB	6.65 KB	0.00 KB (0.00%)
batching.ts	9.44 KB	9.44 KB	0.00 KB (0.00%)
brand.ts	6.33 KB	6.33 KB	0.00 KB (0.00%)
cache.ts	10.20 KB	10.20 KB	0.00 KB (0.00%)
config.ts	20.34 KB	20.34 KB	0.00 KB (0.00%)
differ.ts	19.95 KB	19.95 KB	0.00 KB (0.00%)
http-client.ts	21.04 KB	21.04 KB	0.00 KB (0.00%)
logger.ts	10.35 KB	10.35 KB	0.00 KB (0.00%)
metric.ts	8.58 KB	8.58 KB	0.00 KB (0.00%)
optic.ts	7.34 KB	7.34 KB	0.00 KB (0.00%)
pubsub.ts	14.49 KB	14.49 KB	0.00 KB (0.00%)
queue.ts	11.15 KB	11.15 KB	0.00 KB (0.00%)
schedule.ts	10.33 KB	10.33 KB	0.00 KB (0.00%)
schema-class.ts	18.88 KB	18.88 KB	0.00 KB (0.00%)
schema-fromJsonSchemaDocument.ts	28.69 KB	28.69 KB	0.00 KB (0.00%)
schema-representation-roundtrip.ts	25.01 KB	25.01 KB	0.00 KB (0.00%)
schema-string-transformation.ts	13.01 KB	13.01 KB	0.00 KB (0.00%)
schema-string.ts	10.66 KB	10.66 KB	0.00 KB (0.00%)
schema-template-literal.ts	14.87 KB	14.87 KB	0.00 KB (0.00%)
schema-toArbitraryLazy.ts	21.67 KB	21.67 KB	0.00 KB (0.00%)
schema-toCodeDocument.ts	24.10 KB	24.10 KB	0.00 KB (0.00%)
schema-toCodecJson.ts	18.93 KB	18.93 KB	0.00 KB (0.00%)
schema-toEquivalence.ts	18.74 KB	18.74 KB	0.00 KB (0.00%)
schema-toFormatter.ts	18.61 KB	18.61 KB	0.00 KB (0.00%)
schema-toJsonSchemaDocument.ts	22.36 KB	22.36 KB	0.00 KB (0.00%)
schema-toRepresentation.ts	19.28 KB	19.28 KB	0.00 KB (0.00%)
schema.ts	18.14 KB	18.14 KB	0.00 KB (0.00%)
stm.ts	12.13 KB	12.13 KB	0.00 KB (0.00%)
stream.ts	9.38 KB	9.38 KB	0.00 KB (0.00%)