feat(deepctl-core): use dg alias in plugin venv ABI mismatch warning

[lukeocodes]

Summary

Two release-infrastructure fixes that need to land before #46 (release-please's chore: release main) is merged. Without this, pip install deepctl==0.2.19 will fail to resolve dependencies for every user.

What's broken

🔴 Install-blocker: deepctl-cmd-debug-toolkit is a phantom package

The toolkit subcommand was added in 768f34f (feat(debug): add toolkit subcommand for deepgram/support-toolkit scripts). The commit:

• ✅ Created packages/deepctl-cmd-debug-toolkit/ with pyproject.toml, src/, etc.
• ✅ Added deepctl-cmd-debug-toolkit>=0.0.1 to the umbrella pyproject.toml dependencies
• ✅ Added [tool.uv.sources] workspace mapping
• ❌ Did not register the package in release-please-config.json
• ❌ Did not register the package in .release-please-manifest.json

Result: the package has never been built or published. pip install deepctl-cmd-debug-toolkit returns Not Found on PyPI today. When deepctl 0.2.19 publishes with deepctl-cmd-debug-toolkit>=0.0.1 in its dependency list, pip will try to resolve that and fail with a missing-distribution error.

AGENTS.md step 6 calls out exactly this set of files as the workspace integration checklist for new packages — it just wasn't followed.

🟡 deepctl-core's plugin warning never reaches PyPI users

fb22d8a (the squash merge of #42) added _warn_if_plugin_venv_python_mismatch() to deepctl-core's PluginManager. But its squash-merge body included markdown tables and ## Summary / ## What lands headings, and conventional-commits-parser choked on it. The release-please run logs show:

❯ commit could not be parsed: fb22d8acace66e5c346f3de1e7d0ee0d87236577 feat(homebrew): homebrew tap support (#42)

release-please skipped the commit entirely. So deepctl-core stayed at 0.2.8 in the manifest, no bump, no PyPI release. The umbrella deepctl 0.2.19 will publish with deepctl-core>=0.1.10 which pip resolves to PyPI's 0.2.8 — the version before the plugin warning was added. The warning code is on main but no PyPI user gets it.

Fixes in this PR

1. Register deepctl-cmd-debug-toolkit with release-please.

   • .github/release-please-config.json — add the package block (matches the convention every other sub-package uses)
   • .github/.release-please-manifest.json — add \"packages/deepctl-cmd-debug-toolkit\": \"0.0.0\" so release-please's first release bumps it to 0.0.1 (matches pyproject.toml)

2. Trigger deepctl-core release with a parseable conventional commit.

   Tweaks the plugin warning's remediation hint from deepctl plugin install to dg plugin install — the canonical user-facing alias used everywhere else in user messages and docs. Small real improvement. The squash-merge title feat(deepctl-core): ... parses cleanly and gives release-please a path-attributable feat on packages/deepctl-core/* to detect.

3. Regenerate stale READMEs.

   scripts/generate_readmes.py --check flagged 3 stale READMEs on main (root, deepctl-cmd-listen, deepctl-cmd-mcp) plus the missing deepctl-cmd-debug-toolkit/README.md. All four regenerated.

After this merges

release-please will recompute and PR #46's body will look like:

<details><summary>0.2.19</summary>          # deepctl root
<details><summary>deepctl-cmd-debug-toolkit: 0.0.1</summary>   # NEW — fixes the install
<details><summary>deepctl-core: 0.2.9</summary>                # NEW — ships the plugin warning

Merging #46 then publishes all three to PyPI in one release event, and pip install deepctl==0.2.19 resolves end-to-end.

Verification

• ruff format --check src/ packages/*/src — 112 files already formatted
• ruff check src/ packages/*/src — clean
• mypy --strict src/ packages/*/src — clean (112 source files)
• python scripts/generate_readmes.py --check — all current
• 4 plugin-warning tests still pass (test message regex doesn't depend on deepctl vs dg)

Pre-existing comments / docstrings

A couple of necessary comments still in this PR were retained per project convention:

• _warn_if_plugin_venv_python_mismatch docstring — Category 3, documents the when (Homebrew Python upgrade scenario), the why-warn-instead-of-block contract, and None semantics. Same justification as in feat: add Homebrew tap support with release auto-bump and plugin Python ABI guard #42.
• The text change is one character (deepctl → dg) and a minor improvement, not a behavioral change.