claude-code-chat-browser: write the [0.2.0] changelog section for the lock-order doc and the concurrency and parity tests #141

Sprint Item

is-11 of 13 — Task — land first Thursday (PR 1 of 3, docs-only)

Block Relations

Calendar Day

Thursday, July 30, 2026 (PR 1 of 3 — docs-only)

Planned Effort

3 story points (Task) — sprint item is-11

Problem

CHANGELOG.md has an empty [Unreleased] section (lines 7-8) and documents only v0.1.0.

Week 30 shipped three merged PRs that are not recorded anywhere:

None of it appears under [Unreleased] or a [0.2.0] heading.

This repository has no surviving issues at any severity. Release hygiene is the entire scope of its week.

Goal

One docs-only PR writing an accurate [0.2.0] section, so item is-12's Release notes can be copied straight out of it.

Scope

Part A — read before writing

• docs/architecture.md lines 160-188 for the lock inventory and forbidden-order rules, so the bullets are accurate rather than approximate.
• The concurrency test imports build_search_index, query_index_hits and reset_background_for_tests from utils/search_index.py and asserts the lock-order invariants the architecture doc describes.
• The parity oracles cover Python utils/md_exporter.py and utils/tool_dispatch.py alongside the JavaScript renderToolResult, using a shared adversarial XSS payload.

Part B — write the section

• ## [0.2.0] - YYYY-MM-DD documenting the lock-order documentation (docs: search-index lock-acquisition order and threading model #138), the search-index concurrency tests (test: search-index concurrency for rebuild, queries, and lock order #139), and the dual-path parity oracle tests (test: parity and input oracles #140).
• Reference the real file paths: docs/architecture.md, tests/test_search_index_concurrency.py, tests/test_dual_path_parity_oracle.py, static/js/render/tool_result/dual_path_parity_oracle.test.js.
• Follow the Keep a Changelog style of the existing [0.1.0] section.

Part C — housekeeping

• Clear [Unreleased]; update the footer compare links.

Out of scope

• The app.py version bump — that belongs to item is-12 (release/v0.2.0).
• The flat utils/ namespace and lock-registry abstraction (Medium) — deferred past July. The success definition asked for a documented lock order with tests; that shipped in Week 30. A registry abstraction is beyond that bar.

Acceptance Criteria

• CHANGELOG.md contains a ## [0.2.0] - YYYY-MM-DD section documenting the lock-order documentation (docs: search-index lock-acquisition order and threading model #138), the search-index concurrency tests (test: search-index concurrency for rebuild, queries, and lock order #139), and the dual-path parity oracle tests (test: parity and input oracles #140).
• Entries reference the real file paths: docs/architecture.md, tests/test_search_index_concurrency.py, tests/test_dual_path_parity_oracle.py, static/js/render/tool_result/dual_path_parity_oracle.test.js.
• The [Unreleased] section is cleared and the footer compare links are updated.
• Docs-only — no version bump in this PR.
• PR approved by at least 1 reviewer.

Verification

# from the claude-code-chat-browser checkout root
git log v0.1.0..HEAD --oneline

• Cross-check each bullet against the real files and the architecture doc's lock inventory — the changelog must describe what shipped, not what was planned.
• Confirm git diff --stat touches only CHANGELOG.md.

References

• Sprint: Week 31 (Jul 27–31, 2026) — Chen item is-11 (3 pt, Task)
• Week 31 weekly plan — claude-code-chat-browser
• Week 31 issue descriptions — claude-code-chat-browser, [0.2.0] changelog
• Eval finding: n/a — this repository has no surviving issues at any severity
• Files: CHANGELOG.md:7-8,9; docs/architecture.md:146-192,160-188; tests/test_search_index_concurrency.py; tests/test_dual_path_parity_oracle.py; static/js/render/tool_result/dual_path_parity_oracle.test.js
• Companion: Thursday is-12 v0.2.0 release, is-13 RELEASING.md
• Week 30 PRs covered: docs: search-index lock-acquisition order and threading model #138, test: search-index concurrency for rebuild, queries, and lock order #139, test: parity and input oracles #140
• Success definition: "Documented lock order backed by concurrency tests, diagnosable failures, deployment doc" — v0.2.0