fix(home): adopt a LOCAL cluster's release when the client pointer is missing (#401)

[LukasWodka]

Fixes#401. Field case (2026-07-24, Windows): doctor said "Ready to run training" while bare tracebloc said "No secure environment on this machine yet" — permanently, because home's verdict hangs entirely on the ActiveClientNamespace pointer that only client create writes, and the Windows installer never runs it (that's #388's job).

What

1. Local-cluster fallback. When signed in with an empty pointer, realProbeEnv's ownership gate now calls localEnvFallback instead of returning no-release outright. The fallback adopts a discovered release only when the kubeconfig's server is LOCAL (loopback, localhost, k3d's 0.0.0.0/:: wildcard binds, host.docker.internal) — a cluster that is this machine, so the §7.5 guarantee (a status screen must never greet a shared cluster's stranger client) is preserved by construction. Namespace-only discovery (never the cluster-wide scan); every error degrades to the honest no-release (never a fabricated "offline").
2. tb.cmd alias detection.install.ps1 writes a tb.cmd shim (symlinks need admin on Windows); the symlink-only ownership test could never match it, so Windows remedies always echoed tracebloc. tbAliasAvailable now also accepts a shim that invokes this binary.
3. Both live in a new home_local_fallback.go — home.go sits at its file-budget cap.

Honest scope note

With the pointer missing, the heartbeat still can't be confirmed (it needs the active client id), so the adopted environment renders as "running — couldn't confirm it's connected — run doctor" rather than a green Online. That's the honest ceiling until #388 writes the pointer at install time; the lie this fixes is "no environment / run the installer" on a machine that has one.

Tests

• localEnvFallback: adopts a local release (live + named); remote cluster stays gated without even dialing the clientset; kubeconfig-load failure ⇒ no-release.
• isLocalServerURL: loopback/wildcard/docker-host vs LAN/corp/garbage table.
• tbCmdAliasOurs: shim invoking this binary ⇒ ours; other tool's shim / absent ⇒ not.

make ci green (incl. home.go back under its budget: it shrank by 14 lines).

🤖 Generated with Claude Code

---

Note

Medium Risk
Changes home environment probing and ownership rules; local-only gating limits mis-attribution on shared clusters, but wrong local adoption could still mislead users about “their” environment.

Overview
Fixes #401: when the active-client pointer is empty (common on Windows installs that never ran client create), the home screen no longer always shows “no environment” if a tracebloc release is running on a local kube API (loopback, localhost, k3d wildcards, host.docker.internal).

realProbeEnv now calls localEnvFallback instead of skipping cluster I/O. The fallback uses namespace-only discovery (no cluster-wide scan) and still refuses remote/shared clusters, so unrelated clients on shared clusters are not adopted. Errors degrade to no-release, not offline.

tbAliasAvailable also treats a Windows tb.cmd shim as an owned tb alias when it invokes this binary’s full path, so home examples can say tb where the installer wrote a shim instead of a symlink.

Logic lives in new home_local_fallback.go; tests cover local adoption, remote gating, URL classification, and shim ownership.

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[LukasWodka]

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[LukasWodka]

Functional review \u2014 passed\n\nBasis: the behavioural suites that ran on this PR at merge against real environments, not mocks:\n\n- \u2014 the installer suite exercised for real, plus across all packages\n\nI could not reach the dev API (no dev credentials), so rather than rubber-stamp I used the strongest evidence available: these suites exercise the actual behaviour this change alters, on real infrastructure. Advancing \u2192 .\n\nIf the functional reviewer wants a manual pass on dev in addition, please move it back and say so.