[4.6] PyPI 1.0.0 release

[RFingAdam]

Acceptance criteria

• All Phase 0–4 milestones closed
• CHANGELOG complete from 0.1.0
• Version bumped to 1.0.0
• Wheels for cp311/cp312/cp313 × 4 platforms uploaded to real PyPI
• pip install atlc3 works on a fresh machine
• Announcement post drafted

[RFingAdam]

Scope clarification (the issue title is stale relative to repo state):

• The repo is currently at 2.2.0 (AGPL-3.0-or-later, see src/lineforge/version.py and the v2.2.0 git tag). "1.0.0" in the title is a milestone label from when this issue was filed — semantically we mean "first production PyPI upload, regardless of internal version".
• Brand also moved: atlc3 → lineforge. pip install atlc3 in the AC should read pip install lineforge; the kernel module is lineforge._kernel.

Current state of release infrastructure:

• .github/workflows/release.yml already exists with maturin wheels for cp311/cp312/cp313 × ubuntu (x86_64/aarch64) / macos (universal2) / windows (x64), plus an sdist build and TestPyPI / PyPI publish jobs (the latter gated on workflow_dispatch input).
• CHANGELOG includes entries from 0.7.1 through 2.2.0.
• Phase 0–3 milestones are mostly closed; [2.14] MCP server end-to-end Claude Desktop verification #8/[3.4/3.5] Coax + round-wire DC L/R parity #9/[3.8] atlc2 parity benchmark suite #12/[audit] Increase test coverage 58% → 90% #20 are the remaining Phase-4 audit items.

Proposed updated acceptance criteria:

• Rename issue title to "Cut first PyPI release"
• Update brand references in AC (pip install lineforge)
• Trigger release.yml with target=testpypi and verify all wheels build + upload
• pip install --index-url https://test.pypi.org/simple lineforge works on a fresh venv
• Sign + tag v2.3.0 (or the next minor) and trigger release.yml with target=pypi
• Announcement post drafted
• Close Phase-4 audit gaps ([2.14] MCP server end-to-end Claude Desktop verification #8, [3.4/3.5] Coax + round-wire DC L/R parity #9, [3.8] atlc2 parity benchmark suite #12, [audit] Increase test coverage 58% → 90% #20) before promoting from TestPyPI → PyPI

Will retitle and update once the rest of the Phase 4 audit gaps are closed.

[RFingAdam]

Test-run on the wheel matrix went well — but TestPyPI publish is gated on trusted-publisher config that hasn't been registered yet.

Workflow status: run 26047896750 — all 5 build jobs ✅ (linux x86_64, linux aarch64, macos universal2, windows x64, sdist). Publish step ❌ with invalid-publisher: valid token, but no corresponding publisher (Publisher with matching claims was not found).

Per `docs/release/PYPI_TRUSTED_PUBLISHER.md`, the one-time TestPyPI setup is:

1. Log in at https://test.pypi.org/manage/account/publishing/
2. Add a new pending publisher with:
   • Project name: `lineforge`
   • Owner: `RFingAdam`
   • Repository: `lineforge`
   • Workflow filename: `release.yml`
   • Environment name: `testpypi`
3. Re-run workflow 26047896750 or trigger a new `gh workflow run release.yml -f target=testpypi`.

The actual wheel matrix is healthy and ready — only the OIDC handshake at the very end fails because PyPI has no record of this repo as a trusted publisher yet. Production PyPI needs the same registration at https://pypi.org/manage/account/publishing/ with `environment: pypi` (gated behind the manual workflow_dispatch input).