v0.5.0 — in-sandbox action discovery

In-sandbox action discovery

Discovery is now a first-class part of the sandbox. Inside runline exec, an actions object lets the agent explore the catalog without leaving the sandbox boot.

actions.list()                  // every "plugin.action" path
actions.list("github")          // filter by plugin
actions.find("create issue")    // ranked fuzzy search (MiniSearch)
actions.describe("github.issue.create")
// → { path, plugin, action, description, signature, inputs }
actions.check("github.issue.create", { owner: "a" })
// → { ok, missing, unknown, typeErrors, signature }   (does NOT call)

Unknown paths throw with did-you-mean suggestions, so typos are self-correcting. Recommended flow: find → describe → check → call.

Also

• Plugin globals and actions.<plugin>.<action>(...) are now both legal forms of the same call.
• MiniSearch is bundled into the sandbox source for fuzzy ranking.

Breaking

• Removed help(), <plugin>.help(), and the proxy's .help shortcut. Use actions.list / find / describe instead.
• HelpEntry.inputs shape changed from formatted string to { type, required, description }.

pi-runline

• Removed the list_runline_actions tool — discovery happens inside execute_runline now.
• Session-start primer rewritten: instead of dumping the full catalog into the system prompt, it names the enabled plugins and teaches the actions.* discovery flow. Real token win on projects with many plugins enabled.