fix: enforce public Scient identity

[yaacovcorcos]

What changed

• fixes Scient-owned public identity at Linux packaging, generated Git/stash names, share-card downloads, UI placeholders, profile fallbacks, CLI guidance, CI labels, and active developer documentation
• removes the stale Synara-branded README/marketing screenshot without fabricating a replacement
• clears the bundled server web-client target before copying a new build so obsolete branded assets cannot survive incremental builds
• adds precise repo-local Scient development-home ignores without hiding canonical .scient/project.json
• strengthens the identity guard for bounded Scient-owned outputs and narrows the PapiLab migration allowlist so unrelated product copy still fails
• extends release smoke coverage to Linux executable and StartupWMClass identity

Why

The LitRev/PapiLab product rename is complete, but several current public and developer surfaces still emitted inherited Synara identity. This PR closes those product-boundary defects while preserving inherited source structure needed for selective upstream intake.

Compatibility boundary

This intentionally does not rename @synara/*, SYNARA_*, Effect/service IDs, persistence identifiers, OpenCode internals, attribution, or accurate upstream references. Antigravity's installed synara-capture hook is also excluded because it needs a separate read-old/write-new compatibility migration.

Validation

• formatting passed
• lint passed with 0 errors (existing warnings only)
• all 9 package typechecks passed
• brand identity guard passed
• script tests: 81/81
• relevant server tests: 138/138
• Codex text-generation isolation: 12/12
• desktop remainder: 187/187
• marketing build passed
• release smoke passed
• git diff --check and git show --check passed

Broad root-suite runner failures were reduced to smallest reproductions and repeated on an untouched origin/main worktree: Turbo's Bun-as-Node shim changes updater/Codex test behavior, and localImageRoute.test.ts has the same grant-state failure on main. No PR-caused failure remained.

Related work

Companion documentation closeout: ScientFactory/Scient#19.