docs: seed CHANGELOG.md (Keep-a-Changelog format) (#74)

Closes Row-2 Phase 3 of the 2026-05-26 estate tech-debt audit chain
for this repo. The 2026-05-26 documentation-debt audit
(hyperpolymath/standards#197) flagged that 180 of 279 estate repos
lacked a CHANGELOG.md (65% gap) — this seed closes that finding here.

The seed:
  - Uses Keep-a-Changelog format with an [Unreleased] section.
  - Buckets the most recent 100 commits by conventional-commit prefix
    (feat/fix/refactor/docs/ci/build) into Added/Fixed/Changed/
    Documentation/CI sections.
  - References standards#206's changelog-reusable.yml + the canonical
    templates/cliff.toml for full-regeneration via git-cliff.

The file is initial — the maintainer can adopt changelog-reusable.yml
in this repo's CI to keep it auto-regenerated, or regenerate manually.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

CHANGELOG.md

@@ -0,0 +1,74 @@
+<!--
+SPDX-License-Identifier: MPL-2.0
+SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell (hyperpolymath)
+-->
+
+# Changelog
+
+All notable changes to `my-lang` will be documented in this file.
+
+This file is generated from conventional commits by the
+[`changelog-reusable.yml`](https://github.com/hyperpolymath/standards/blob/main/.github/workflows/changelog-reusable.yml)
+workflow (`hyperpolymath/standards#206`). Adopt the workflow in this repo's CI to keep this file in sync automatically — see
+[`templates/cliff.toml`](https://github.com/hyperpolymath/standards/blob/main/templates/cliff.toml)
+for the canonical config.
+
+The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/);
+this project aims to follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+
+- feat(solo/stdlib): fs_list_dir(path) -> Array<String> (#56)
+- feat(solo/stdlib): date_today() -> ISO YYYY-MM-DD (UTC) (#54)
+- feat(solo/stdlib): json_parse / json_stringify + fix string escapes (#53)
+- feat(solo/stdlib): string-keyed Map/dict builtins (#49)
+- feat(parser): add MAX_PARSE_EXPR_DEPTH guard + recover partial AST (closes #15) (#21)
+- feat(stdlib): add fs_*/env_args/format builtins + my-cli argv forwarding (#10)
+- feat(stdlib): add fs_*/env_args/format builtins + my-cli argv forwarding (#8)
+- feat(stdlib): add fs_*/env_args/format builtins + my-cli argv forwarding (#2)
+- feat(my-lang): add Ensemble dialect grammar and implement Variant B types
+
+### Fixed
+
+- fix(licence): clear scaffold-placeholder leak (isolated; dirty repo) (#64)
+- fix(vscode): make the packaged .vsix actually load (Refs #62) (#63)
+- fix(vscode-ext): pass real callbacks to registerCommand (affinescript#35 P2) (#60)
+- fix(vscode-ext): correct affinescript compile invocation + document build (#58)
+- fix(ci): pin upload-artifact to valid SHA in hypatia-scan.yml (Refs standards#48) (#50)
+- fix(checker): general non-overflowing AST teardown + measured MAX_EXPR_DEPTH (#37) (#43)
+- fix(ci): sync hypatia-scan.yml to canonical (kill cd-scanner build drift) (#44)
+- fix(ci): Phase-2 fleet submission must not fail the security gate (#42)
+- fix(#34): resolve Hypatia backlog at source; finalize baseline (#35)
+- fix(lib/common): two latent correctness bugs in stdin/radix paths (refs #22) (#24)
+
+### Changed
+
+- perf(checker): memoise environment-independent subexpressions (closes #16) (#31)
+- refactor: wire up dead fields, derive Default, clarify package-mgr stubs (refs #22) (#26)
+- refactor: rename 7-tentacles → frontier-practices, sideline dialects/me
+
+### Documentation
+
+- docs: mark Maps/JSON/Date stdlib rows Shipped in ecosystem roadmap (#59)
+- docs: replace never-built stdlib .my-module/@ffi sketch with reality (#52)
+- docs(checker): reframe MAX_EXPR_DEPTH as a stack-recursion bound (closes #14) (#36)
+- docs(#14) record + fix repeated Hypatia scan noise (#33)
+- docs(readme): add SPDX header, OSSF and GWF badges
+
+### CI
+
+- ci(spark): adopt estate SPARK Theatre Gate (standards#135) (#65)
+- ci(codeql): scan `actions` instead of javascript-typescript (#32)
+- ci(secret-scanner): drop duplicate --fail from trufflehog extra_args (#17)
+- ci(antipattern): fix top-level dir matching + benchmarks/lsp/bench filename allowlists (#7)
+- ci(antipattern): TS check reads .claude/CLAUDE.md exemption table (#6)
+
+## Pre-history
+
+Prior commits to this file's introduction are recorded in git history but not formally classified into Keep-a-Changelog sections. To backfill, run `git cliff -o CHANGELOG.md` locally using the canonical [`cliff.toml`](https://github.com/hyperpolymath/standards/blob/main/templates/cliff.toml) — this is one-shot mechanical work.
+
+---
+
+<!-- This file was seeded by the 2026-05-26 estate tech-debt audit follow-up (Row-2 Phase 3); see [`hyperpolymath/standards/docs/audits/2026-05-26-estate-documentation-debt.md`](https://github.com/hyperpolymath/standards/blob/main/docs/audits/2026-05-26-estate-documentation-debt.md). -->