feat(tui+release): persist vitest memory guard, aggregate root CHANGELOG, lockstep all packages

TUI: vitest memory-guard threshold and on/off toggle now persist to
global settings (vitestAutoKillEnabled / vitestKillThresholdPct), so
they survive dashboard restarts. Stats panel shows the system-memory
used percentage next to used/free. Utilities panel exposes [+/-] to
adjust the threshold in 5% steps (50–99%).

Release: scripts/release.mjs auto-syncs a root CHANGELOG.md aggregated
from every packages/*/CHANGELOG.md, grouped by version with one
sub-block per package.

Versioning: all private @fusion/* packages joined the changesets fixed
group with the public cli + cli-alias and were aligned to 0.2.5, so
every release bumps every package and produces per-package CHANGELOG
entries that the aggregator picks up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.changeset/config.json

@@ -2,7 +2,17 @@
   "$schema": "https://unpkg.com/@changesets/config@3.1.1/schema.json",
   "changelog": "@changesets/cli/changelog",
   "commit": false,
-  "fixed": [["@runfusion/fusion", "runfusion.ai"]],
+  "fixed": [[
+    "@runfusion/fusion",
+    "runfusion.ai",
+    "@fusion/core",
+    "@fusion/dashboard",
+    "@fusion/desktop",
+    "@fusion/engine",
+    "@fusion/mobile",
+    "@fusion/pi-claude-cli",
+    "@fusion/plugin-sdk"
+  ]],
   "linked": [],
   "access": "public",
   "baseBranch": "main",