feat: honor ZCODE_HOME for the config and lazy-session store paths

[jbellis]

Problem

The credentials config path and the lazy-session alias store are pinned to ~/.zcode. A bridge cannot be pointed at an isolated ZCode install (a second account, a container mount, a test fixture) without moving the user's real home directory.

Change

zcodeHomeDir() in utils.ts is the single place that resolves the data root: ZCODE_HOME when set, else <home>/.zcode. ZCODE_CREDS_PATH and the lazy store's storePath() build on it. Default behaviour is unchanged when the variable is unset. The README documents the variable.

The hermetic test setup now clears ZCODE_HOME for the same reason it redirects HOME.

Tests

tests/utils.test.ts and tests/lazy-sessions.test.ts cover the variable set and unset.

🤖 Generated with Claude Code

https://claude.ai/code/session_01DLQ3W2owia4SJBvzxSqvVc

[william0wang]

Reviewed (typecheck pass; targeted tests pass; the lazy store still goes through persist() and the hermetic setup clears ZCODE_HOME — both good).

Requesting one change before merge: the override is partial. zcodeHomeDir() is documented as the single data-root resolver, but these readers still build the real ~/.zcode from module-level homedir()/HOME constants:

• src/config/skill-discovery.ts:45,48,170 (CLI config, plugin cache, user skills scan)
• src/config/mcp-discovery.ts:48,49
• src/config/plugin-commands.ts:19,27
• src/i18n.ts:57 (settings.json locale detection)
• src/tasks-index.ts:355 (the App's tasks-index.sqlite backing the remote session list)

With ZCODE_HOME pointed at an isolated install, credentials and lazy sessions follow the override while plugins/skills/MCP servers/locale/session-listing still read the real home — a silently split brain for exactly the second-account/container case the README promises. Either route them through zcodeHomeDir() (preferred) or narrow the README claim to "credentials and the lazy-session store".

[jbellis]

Thanks! Addressed in a8ac07a — went with the preferred option: every flagged reader now goes through zcodeHomeDir().

The three identical CLI-config/plugin-cache path constants became shared per-call helpers (zcodeCliConfigPath() / zcodePluginCacheDir()) in utils.ts; the user-skills scan reads <zcode-home>/skills; i18n's setting.json read and tasks-index's workspace exclusion follow the override too. ~/.agents/skills deliberately stays on the real home — it's a cross-agent convention, not part of the ZCode data root. The README row now lists every follower instead of narrowing the claim.

Each affected module gained a ZCODE_HOME test that proves the real home is ignored while the override is honored (the i18n one required tightening that suite's fs mock from suffix-match to exact-match so it can actually discriminate the two roots).