[pkking]

Summary

• Add project-authored Mocha landscape and separately composed portrait wallpapers, editable SVG sources, and provenance/usage notes.
• Point only the wallpaper portion of the Noctalia desktop template at these assets and their per-monitor pools; add offline asset/profile contract tests.

Scope and behavior

The existing B profile points at ~/.local/share/wallpapers/{landscape,portrait}, but its current preflight guard hard-codes ~/.local/share/wallpapers/ezwallpaper-mocha/{landscape,portrait}. Editing the profile alone does not make that guard support arbitrary paths. This PR documents/tests that existing mismatch; it does not fix B's paths or behavior. It changes only the Mocha assets, Noctalia template, and their contract/documentation. It does not claim that merged B automatically uses these assets.

Noctalia native wallpaper configuration is available as a static configuration, but wallpaper.automation.enabled = false remains unchanged, so no timer/rotation is automatically enabled. The separate ezwallpaper scheduler must not be run together with Noctalia automation. No profile/timer is enabled or installed by this PR.

Validation

• Mocha asset/contract tests: 5 passed.
• Existing B safety tests: 8 passed.
• Rendered Noctalia template output checked; both supplied PNGs identified/decoded at 3840×2160 and 2160×3840.
• git diff --check: passed.
• No chezmoi apply, live-session or visual acceptance was performed. This is not a claim of visual/runtime validation.

Related to #84 (already closed; no issue comment posted). No issue is closed by this PR.