Migrate hook namespace + sections to colon delimiter (mxdev 5.3.1+) #74

Context

mxdev 5.3.1 (PR #88) fixed a long-standing bug where hook namespaces silently swallowed any package whose name merely started with them (e.g. a uv hook claiming uvst.addon). The fix anchored section matching: hook sections must now be named exactly [namespace] or [namespace:subsection] — a colon, because colons cannot appear in Python distribution names.

That broke mxmake. Under 5.3.1, [mxmake-env], [mxmake-mxenv], and every [mxmake-{template}] section is reclassified as a package, then trips ValueError(\"Section mxmake-env has no URL set!\") on the first run.

mxdev 5.3.2 (in PR #89) restores the hyphen form with a deprecation warning, so mxmake keeps working without changes. This issue tracks the eventual migration to the canonical colon syntax.

What's affected in mxmake

• src/mxmake/utils.py:6 — NAMESPACE = \"mxmake-\" (trailing hyphen baked into the namespace)
• src/mxmake/hook.py:25 — namespace: str = NAMESPACE
• src/mxmake/templates/mx.ini — emits [mxmake-env], [mxmake-{{ template[\"name\"] }}]
• src/mxmake/templates.py:123 — self.config.hooks.get(ns_name(self.name), {})
• Every existing mxmake user's generated mx.ini

With mxdev 5.3.2, all of the above logs a deprecation warning but continues to work.

Suggested migration path

1. NAMESPACE = \"mxmake-\" → NAMESPACE = \"mxmake\"
2. ns_name(name) → f\"mxmake:{name}\" for section names
   • Settings keys inside [settings] (e.g. mxmake-templates, mxmake-test-runner) are unaffected by mxdev's change — they are keys, not section names. Renaming them to mxmake:templates etc. for consistency is optional and would itself need its own deprecation cycle.
3. Update src/mxmake/templates/mx.ini → [mxmake:env], [mxmake:{{ template[\"name\"] }}]
4. Adjust template generation so both old [mxmake-*] and new [mxmake:*] keys are recognized during the transition (or accept that users must regenerate)
5. Pin mxdev>=5.3.2 in pyproject.toml (currently >=4.0.2) once mxdev 5.3.2 is released
6. Add a release-note section documenting the rename for end users — they'll need to either regenerate from a new mxmake or rename [mxmake-*] → [mxmake:*] in their mx.ini

Severity / urgency

Not urgent: mxdev 5.3.2 keeps everything working with a warning. Migration can be planned for the next mxmake feature release.

Refs

• mxdev fix PR: Fix hook namespace swallowing packages with a matching name prefix mxdev#88
• mxdev deprecation-restore PR: Re-accept hyphen-delimited hook sections with deprecation warning mxdev#89