D80 — Versioning reset to 0.x: the public line starts at v0.1.0

Status: implemented (2026-07-18).

Context. D79.b carried the internal pre-publication version (2.1.2) into the release-please manifest, so the first public release came out as v2.2.0. Two problems. First, semantics: the project is a beta, and a 2.x number signals a maturity (two stable major cycles behind it) that the public project does not have — the 2.x history belongs to the archived internal line, not to what users can observe. Second, tooling: the module path is github.com/BeppeTemp/cartographer without the /v2 suffix that Go modules require for v2+ tags, so v2.2.0 was invisible to go install/go get (@latest resolved to a pseudo-version of main, never to the release).

Decision. The v2.x public line is retired and public versioning restarts at v0.1.0:

a) Manifest reset to 0.0.0 and bump-minor-pre-major: true + initial-version: 0.1.0 in release-please-config.json (with no tag matching the manifest, release-please takes the initial-release path and would otherwise default to 1.0.0): the next release PR computes 0.1.0. Pre-1.0 semantics: breaking changes bump the minor (0.x convention), fixes bump the patch; 1.0.0 when the MCP tool surface and CLI stabilize.

b) The v2.2.0 GitHub release and tag are deleted (operator action: they predate this decision and would otherwise remain "latest" and confuse the badge and releases/latest). The ghcr.io image tag v2.2.0 and the Homebrew cask 2.2.0 are left as-is — registries are append-only in spirit and the next release overwrites latest/the cask. Homebrew will not auto-downgrade; irrelevant at current adoption.

c) CHANGELOG.md reset with a pointer to this entry; beta disclaimer added to the README (top, GitHub alert) and the pre-1.0 policy stated in CONTRIBUTING.md.

Rationale. A 0.x number is the only version string that tells the truth about stability, fixes the Go-tooling invisibility for free (0.x tags need no module-path suffix), and preserves headroom: the eventual real v1.0.0/v2.0.0 stay meaningful. Resetting now, days after publication and before any registry (MCP Registry publish shipped after v2.2.0 and never ran), is the cheapest moment it will ever be.