fix: v2.3.1 — correct version, say why a plugin update failed, gitignored files in Files

- v2.3.0's tree reported 2.2.1, so every install saw an update forever;
  package.json, the lockfile, openapi.yaml, the CLAUDE.md marker and the
  snapshot now read 2.3.1
- A failed plugin-update step records the tail of the command's stdout and
  stderr plus its exit code or signal (failureText); plugin-bootstrap.js
  prints its refusal on stdout, which the verdict used to drop. Update all
  uses the same text
- updates.test.js never applies an update: it skips when the checkout is
  behind a release (apply ran npm run setup and pruned dev dependencies)
- Files tree lists gitignored files and folders, named in orange
  (addIgnored in git-diff.js); change-tree rows indent in whole steps

scripts/cc-update-all-helper.js

@@ -26,6 +26,8 @@ const fs = require("fs");
 const { rotateIfLarge } = require("./log-rotate");
 const path = require("path");
 const { execFileSync, spawnSync } = require("child_process");
+// What a failed command printed — plugin-bootstrap.js says why on STDOUT.
+const { failureText } = require("./plugin-update-helper");
 
 const [, , runtimeDirArg, planJson] = process.argv;
 
@@ -229,7 +231,7 @@ function main() {
   } catch (err) {
     // A marketplace that can't be refreshed (offline, auth) does not stop the
     // batch: the plugins may still have updates from the marketplaces that did.
-    finishStep(mktStep, "failed", { error: String(err.stderr || err.message).slice(0, 2000) });
+    finishStep(mktStep, "failed", { error: failureText(err).slice(0, 2000) });
   }
 
   const self = plan.selfPlugin;
@@ -243,7 +245,7 @@ function main() {
       run(claude, ["plugin", "update", id, "-y"], 600_000);
       finishStep(step, "ok");
     } catch (err) {
-      finishStep(step, "failed", { error: String(err.stderr || err.message).slice(0, 2000) });
+      finishStep(step, "failed", { error: failureText(err).slice(0, 2000) });
     }
   }
 
@@ -253,7 +255,7 @@ function main() {
     try {
       run(claude, ["plugin", "update", selfId, "-y"], 600_000);
     } catch (err) {
-      finishStep(step, "failed", { error: String(err.stderr || err.message).slice(0, 2000) });
+      finishStep(step, "failed", { error: failureText(err).slice(0, 2000) });
       reloadPanes();
       state.status = "failed";
       state.finished_at = new Date().toISOString();
@@ -281,7 +283,7 @@ function main() {
       } catch (err) {
         log(`bootstrap failed: ${err.message}`);
         state.status = "failed";
-        state.bootstrap_error = String(err.stderr || err.message).slice(0, 2000);
+        state.bootstrap_error = failureText(err).slice(0, 2000);
         state.note = "the old server was stopped; run /agenthub-update to recover";
         flush();
       }