MainSequence Desktop 0.4.12 preview

Fixes agent icons that never appeared. An agent whose Command Center icon record has
no idle image (Back Office Helper on the tested backend) made the icon cache read a
missing previous entry; the exception discarded the whole batch of four agents, so
agents with valid icons in the same batch, such as MainSequence Tutorial Helper,
showed none in the list, details, composer band or tool rows, also after Refresh.
Each agent's record is now handled on its own, and a malformed one only affects that
agent.

Validation: 86 Node tests, nine native Desktop simulator tests, loader validation and
distribution checks passed. A replay of the real local-backend responses through
Desktop's bundled Code 2.1.299 engine confirmed the signed-in header, all seven
agents, the Tutorial Helper icon in the list, after Refresh and in details, Talk
prefilling /ms @mainsequence-tutorial-helper , the composer band icon with Switch
agent and End, the composer re-addressed after a reply, the running tool-row icon,
and both connected MCPs with 105 registered tools. Session allocation and messages
were synthesized in that replay, so no backend state was created.

Bundles devtools 0.2.8. Update from the MainSequence marketplace and reload the
plugin in the Code chat. Node 22+ required.

Source revision: 3c5e7b9. Archive SHA-256: 6122ab4c382efe7d727c875323a27c5c1550075e3a982038dcc443ed4085f2b0.