docs: add CHANGELOG.md

CHANGELOG.md

@@ -0,0 +1,55 @@
+# Changelog
+
+Notable changes to the TORPC specification, its per-method mappings and its conformance vectors.
+
+The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/). Versioning is the
+specification's own, defined in [GOVERNANCE.md](./GOVERNANCE.md): an editorial change gets a dated
+entry and no version bump, a backward-compatible addition gets a minor bump, and anything that can
+make a conforming implementation non-conforming gets a major one. Governance also states that
+merging the text is not a release — a release is a tag plus the version bump — which makes this file
+the release notes that policy refers to.
+
+No tag has been cut in this repository yet, so everything below sits under Unreleased. v1 is being
+tagged separately: rather than date a v1 entry to a tag that does not exist, this file keeps v1
+unreleased, and the section will be renamed with the tag's own date when the tag lands.
+
+## Unreleased
+
+### Added
+
+- **EVM RPC Compression v1**, status **Draft**, in [`specs/evm-v1.md`](./specs/evm-v1.md). Opt-in
+  per request through two HTTP headers, `Accept-Token-Tier` on the request and `Token-Tier` on the
+  response, with no change to the JSON-RPC 2.0 envelope and no new methods or error codes. Tiers 0
+  through 2 are normative; tiers at or above 3 are reserved and can only be given meaning by a
+  specification release. The document fixes best-effort downgrade, transformation-failure
+  passthrough, verbatim passthrough of JSON-RPC errors and of methods carrying no ruleset,
+  reversibility by re-query, determinism, and the minimum-tier rule for batched responses.
+- **Per-method mappings** under [`specs/methods/`](./specs/methods/): eight mapping documents
+  covering **23 JSON-RPC methods**, each stating the field-level transform at T1 and at T2. Of those
+  23 methods, ten reach tier 2 and the remaining thirteen are tier 1 only. The coverage table in
+  [`specs/methods/README.md`](./specs/methods/README.md) lists 21 rows, because
+  `eth_getTransactionByHash.md` also covers `eth_getTransactionByBlockHashAndIndex` and
+  `eth_getTransactionByBlockNumberAndIndex`, which have no row of their own. The same directory
+  carries the table of methods deliberately left out of v1, with the reason for each.
+- **Conformance vectors and runner** in [`conformance/`](./conformance/): a dependency-free runner
+  that drives an implementation through an adapter, and one golden vector,
+  `conformance/golden/eth_getTransactionReceipt/hex-strip-and-drop-service.json`. One case is not
+  coverage. Certification is not open, no implementation is certified, and nothing may be described
+  as "TORPC Conformant" yet; the gate for opening it is in [GOVERNANCE.md](./GOVERNANCE.md).
+- Repository documents: [README.md](./README.md), [GOVERNANCE.md](./GOVERNANCE.md),
+  [DECISIONS.md](./DECISIONS.md), [CONTRIBUTING.md](./CONTRIBUTING.md),
+  [TRADEMARKS.md](./TRADEMARKS.md), [SECURITY.md](./SECURITY.md), and the non-normative whitepaper
+  under [`whitepaper/`](./whitepaper/). Everything in this repository is CC0-1.0.
+
+### Changed
+
+- The reference packages are named as they are actually published, both under the `@w3tech.io`
+  scope. The codec is
+  [`@w3tech.io/torpc-decoder`](https://www.npmjs.com/package/@w3tech.io/torpc-decoder) on npm, with
+  the install line in the README. The ruleset library is renamed from `@torpc/toevm-rules` to
+  `@w3tech.io/torpc-toevm-rules`; it stays unpublished, so that name is the in-repository name and
+  no package stands behind it on any registry. README, GOVERNANCE and TRADEMARKS previously used the
+  names `@torpc/decoder` and `@torpc/toevm-rules`; neither exists on any registry, and the `@torpc`
+  scope is not used at all.
+- The reserved npm scope in [TRADEMARKS.md](./TRADEMARKS.md) is `@w3tech.io`, which is where the
+  reference packages are published. The previous text reserved a scope that holds nothing.