[DTALEX66]

What this is

The cosmic UI layer for the Avalonia desktop, committed and pushed so it is under version control
and on the remote. Until this branch, the work existed only as uncommitted changes in the
minimax-aaos-cosmic-ui-20261001 worktree — no commit, no stash, and no remote branch held it, so a
removal of that worktree would have lost 353 added lines.

Draft on purpose. Author's work, committed on their behalf: the changes are as found. If the
author prefers a different shape — a different base, a squash, an amended message, the second
commit dropped — say so and it will be redone. Only tests/test_aaos_icon_b10_contract.py in the
second commit was written here, to fix a failing assertion described below.

Commits

Commit	Scope	CI
fec7a18f	13 files: 7 source, 6 tests — the work as found	success, including desktop-vnext, desktop-fast, desktop-build, windows-runtime-smoke, browser-smoke, wheel-smoke, rust-vnext, contracts-vnext, py-compat (3.11 and 3.13), migration-targeted, security-targeted, format-targeted
627e74ff	1 file: tests/test_aaos_icon_b10_contract.py	success — test (3.12), gateplan, lint, a0-gates. The heavy jobs are correctly skipped for a test-only change

What changed

File	Change
AaosBackdrop.cs	a real spatial layer under the glass: opaque theme base, a deterministic star field instead of random noise or a particle simulation, concentric orbit rings from the grid brush
MainWindow.axaml	shell refactored into a topbar and a context sidebar; rail labels present but hidden so the narrow-width contract still holds; home cards moved onto the frame grid
MainWindow.axaml.cs	navigation wiring for the new shell
ThemePalette.cs	a third palette, 深空主题 / DeepSpace; Apply() moves from a two-way choice to a switch over three tables
Themes/AaosTheme.axaml	declares the new brushes
Views/SourceReaderView.axaml	same treatment for the reader
Program.cs	entry adjustment
six tests/* files	the affected navigation and layout contracts

Two properties worth noting for review:

• Accessibility improved, not decorated: AutomationProperties.Name is set on the navigation and
  action buttons, so controls are reachable by name rather than only by position.
• Unconnected surfaces now say so. The workspace tree, file/document/trash, personal memory and
  knowledge-graph panels read "waiting for the Core projection" or "not yet built" rather than
  presenting an empty success. That matches the production contract's rule that a surface which is
  not connected must render as not connected —
  docs/current/AAOS-PRODUCTION-HTTP-CONTRACT-20261001.md §8, on PR Measure production multiformat reachability, fix launcher credential identity, publish HTTP contract #157.

The one assertion this branch had to fix

The first commit's CI failed on exactly one test:

tests/test_aaos_icon_b10_contract.py::test_icon_stroke_and_foreground_follow_both_theme_palettes
    assert palettes.count('["AaosIvoryBrush"]') == 2
E   assert 3 == 2

The assertion was written when two palettes existed; the third palette makes three definitions of
the brush. The behaviour is correct and the assertion was describing the palette count rather than
the rule it tested. It now states the rule — one ivory-brush definition per palette table, read
from the declarations — so it survives a fourth palette while still failing if a palette forgets the
brush. The three palette tables were first verified to be structurally identical (34 lines each),
so a complete third palette was added rather than a partial one.

That file is outside the six this branch already touched, which is why the first local run did not
catch it.

Verification and what is not claimed

• CI is green on both commits, read back at their exact SHAs as listed above.
• The six affected contract files pass locally: 229 passed.
• A local run of the whole suite also reports six failures in test_diagnostics_api.py and
  test_release_manifest.py. These are the known host-environment class recorded in
  AAOS-ERRORS-BLOCKERS-20261001.md — one asserts that diagnostics carry no absolute-path marker
  while this worktree's own path contains D:\, and the others depend on a release-identity.json
  that is absent here. CI, which is clean, reported none of them, and none of the three files
  touched by those tests is in this branch's diff.
• No rendering evidence is claimed. Nothing here says the visuals match the design masters; the
  tests are structural contracts, not screenshots. The UI fidelity question the errors document
  raises under "正式 UI" is untouched by this PR.

Relationship to the other branches

main 59498723  ->  codex/Audit 1a981a44  ->  this branch 627e74ff
                              ^
                              +-- codex/aaos-ui-phase2-20261001 is also at 1a981a44

codex/aaos-ui-phase2-20261001 exists on the remote but is identical to codex/Audit — it
carries no UI work of its own. This branch is the first commit that actually contains the cosmic UI
changes. Based against codex/Audit, the newest of the two.

[DTALEX66]

Frozen as donor material (owner decision, 2026-10-06). The product mainline is Tauri/React, and the reuse/copy of this desktop work is already in place: src-tauri/src/main.rs path-includes desktop/src-tauri/src/{backend,job,protocol,runtime}.rs, and AGENTS.md records the formal host as reusing the existing desktop/ lifecycle. The branch is preserved unfrozen-in-repo but this PR will not be merged; its cosmic UI layer and four-theme model stay with the frozen Avalonia donor. Reopen if the donor is ever revived.