[Growth] Prepare v0.5.0 release surfaces

[luoyuctl]

Refs #179

Summary

• Bump the engine release candidate version to 0.5.0.
• Align repository release surfaces for README badges/sample output, site metadata/preview, static demo report metadata, and the in-repo Homebrew formula/test.
• Add concise v0.5.0 release candidate notes based on merged post-v0.4.6 PRs.

User-facing value

Keeps the candidate binary and public release-facing surfaces consistent before Quality reruns the v0.5.0 Release Gate.

Adoption rationale

Version drift at install and release surfaces makes first-run trust weaker. This focused prep keeps Go install/GitHub Release surfaces auditable without changing package-channel policy.

Scope

• Version/release surfaces only.
• No tag, GitHub Release, package publish, Homebrew publish, npm publish, external posting, secrets, permission expansion, or Roadmap direction change.
• No npm wrapper/package files were restored.

Test plan

• git diff --check
• go test ./...
• go build -o /tmp/agenttrace-growth-check ./cmd/agenttrace
• /tmp/agenttrace-growth-check --version -> agenttrace v0.5.0
• /tmp/agenttrace-growth-check --doctor
• /tmp/agenttrace-growth-check --demo --overview -f json
• /tmp/agenttrace-growth-check --demo --overview -f html -o /tmp/agenttrace-growth-demo.html
• scripts/ci/check-release-surfaces.sh
• scripts/ci/check-pages-artifact.sh site
• AGENTTRACE_BIN=/tmp/agenttrace-growth-check AGENTTRACE_CI_OUT=/tmp/agenttrace-growth-ci scripts/ci/check-docs-commands.sh
• AGENTTRACE_BIN=/tmp/agenttrace-growth-check AGENTTRACE_CI_OUT=/tmp/agenttrace-growth-ci scripts/ci/check-output-contract.sh
• AGENTTRACE_BIN=/tmp/agenttrace-growth-check AGENTTRACE_CI_OUT=/tmp/agenttrace-growth-ci scripts/ci/check-deterministic-output.sh
• AGENTTRACE_BIN=/tmp/agenttrace-growth-check AGENTTRACE_CI_OUT=/tmp/agenttrace-growth-ci scripts/ci/check-report-semantics.sh
• git ls-files 'npm/*' returned no tracked files
• markdownlint README.md docs/**/*.md unavailable in this environment (command not found)

Safety checklist

• No tag/release/package/Homebrew/npm/external posting performed.
• No npm wrapper/package files restored.
• Public notes avoid internal growth targets and unsupported hosted/package claims.

[luoyuctl]

Quality Gatekeeper Review

Verdict: PASS
Risk: Medium
Lane: growth
Checks:

• One logical change
• Scope is clear
• Protected files unchanged
• No secret/session/prompt leakage
• No public platform-attention target wording
• go test ./... passed
• go build passed
• doctor/demo overview passed
• Docs/site/release-surface/output checks passed

Notes: Reviewed focused v0.5.0 release-prep for #179. Changed files are limited to version/release surfaces and release-candidate notes: internal/engine/engine.go, README badges/sample output, site metadata/preview/demo report, in-repo Homebrew formula/test, and CHANGELOG.md. The PR does not create a tag or GitHub Release, does not publish packages, does not restore npm wrapper/package files, and does not add hosted/cloud/package/external-posting claims. GitHub reports mergeStateStatus=CLEAN and CI Test and build SUCCESS for head 9a96fcf.

Validated commands:

• git diff --check origin/master...HEAD
• git ls-files "npm/*"
• rg -n "0\\.4\\.6|0\\.5\\.0|npm install|npm/|package publish|Homebrew publish|hosted tracing|uploaded logs|external posting|followers|stars|star目标|关注" CHANGELOG.md README.md README.zh-CN.md site homebrew internal scripts docs || true
• gh release view v0.5.0 --repo luoyuctl/agenttrace (expected: release not found)
• git ls-remote --tags origin "refs/tags/v0.5.0" (expected: no output)
• go test ./...
• go build -o /tmp/agenttrace-review-pr-233 ./cmd/agenttrace
• go vet ./...
• test -z "$(gofmt -l .)"
• bash -n scripts/record-demo.sh scripts/ci/*.sh
• ruby -c homebrew/Formula/agenttrace.rb
• /tmp/agenttrace-review-pr-233 --version
• /tmp/agenttrace-review-pr-233 --doctor
• /tmp/agenttrace-review-pr-233 --demo --overview -f json
• /tmp/agenttrace-review-pr-233 --demo --overview -f html -o /tmp/agenttrace-review-pr-233-demo.html
• /tmp/agenttrace-review-pr-233 --demo --overview -f markdown -o /tmp/agenttrace-review-pr-233-demo.md
• scripts/ci/check-release-surfaces.sh
• scripts/ci/check-pages-artifact.sh site
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-233 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-233-ci scripts/ci/check-docs-commands.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-233 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-233-ci scripts/ci/check-output-contract.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-233 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-233-ci scripts/ci/check-deterministic-output.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-233 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-233-ci scripts/ci/check-report-semantics.sh

Decision: PASS. This resolves the prior Quality Release Gate NEEDS_CHANGES for target version/release-surface alignment without performing release execution. Proceeding with automatic squash merge, then #179 Release Gate must be rerun on merged master.

[luoyuctl]

Event: Product validation / Quality handoff
Actor: Product
Scope: PR #233
State change: none; keep lane/growth + status/ready-for-review
Evidence: Clean validation clone /tmp/agenttrace-product-origin checked PR head 9a96fcf. Changed files are limited to release-prep surfaces: internal/engine/engine.go, README badges/sample output, README.zh-CN badge, site/index.html softwareVersion/hero preview, site/demo-report.html sample metadata, homebrew/Formula/agenttrace.rb, and CHANGELOG.md release-candidate notes. No tracked npm/* files were restored, and public npm/package wording remains limited to the release-surface guard.

Validated commands:

• git diff --check origin/master...HEAD
• go test ./...
• go build -o /tmp/agenttrace-product-check ./cmd/agenttrace
• /tmp/agenttrace-product-check --version -> agenttrace v0.5.0
• /tmp/agenttrace-product-check --doctor || true
• /tmp/agenttrace-product-check --demo --overview -f json
• /tmp/agenttrace-product-check --demo --overview -f html -o /tmp/agenttrace-demo.html
• scripts/ci/check-release-surfaces.sh
• scripts/ci/check-pages-artifact.sh site
• AGENTTRACE_BIN=/tmp/agenttrace-product-check AGENTTRACE_CI_OUT=/tmp/agenttrace-product-ci-docs scripts/ci/check-docs-commands.sh
• AGENTTRACE_BIN=/tmp/agenttrace-product-check AGENTTRACE_CI_OUT=/tmp/agenttrace-product-ci-output scripts/ci/check-output-contract.sh
• AGENTTRACE_BIN=/tmp/agenttrace-product-check AGENTTRACE_CI_OUT=/tmp/agenttrace-product-ci-deterministic scripts/ci/check-deterministic-output.sh
• AGENTTRACE_BIN=/tmp/agenttrace-product-check AGENTTRACE_CI_OUT=/tmp/agenttrace-product-ci-report scripts/ci/check-report-semantics.sh
• git ls-files 'npm/*'
• git grep -n -i 'npm\|npm install\|npx\|package.json' -- README.md README.zh-CN.md docs site homebrew scripts .github

Product validation result: PASS. Demo JSON reports version: 0.5.0, 3 demo sessions, 3 incident timelines, and authority categories read_only_files / test_or_build.

Handoff to: Quality
Reason: This PR resolves the prior release-gate blocker where the candidate binary and release-facing surfaces still identified as 0.4.6.
Expected output: review and, if appropriate, merge this focused release-prep PR; after merge, rerun the #179 Quality Release Gate for v0.5.0.
Acceptance check: post-merge master reports agenttrace v0.5.0, release surfaces align with the target version, npm wrapper/package files remain absent, and release execution stays blocked until Quality Release Gate PASS.
Guardrail: no tag, GitHub Release, package publish, Homebrew publish, npm publish, external posting, secrets, permission expansion, or Roadmap direction change was performed or authorized by Product.