fix(web): migrate feature colors and status mappings to semantic tokens

[jeanduplessis]

Problem

Feature code maintains parallel palettes using raw Tailwind families, local OKLCH, hardcoded black/white, alpha surfaces, and incorrect domain mappings such as emerald, amber, zinc, or purple outside VS Code.

Remediation action

Replace feature-local colors with canonical surface, foreground, link, syntax, diff, and status-domain tokens.

Representative scope

• apps/web/src/components/shared/Banner.tsx:13
• apps/web/src/components/organizations/UpgradeTrialDialog.tsx:115
• apps/web/src/components/subscriptions/SubscriptionStatusBadge.tsx:4
• apps/web/src/components/cloud-agent-next/SessionsList.tsx:53
• apps/web/src/components/deployments/BuildLogViewer.tsx:64
• apps/web/src/components/security-agent/SeverityBadge.tsx:13
• apps/web/src/app/(app)/claw/components/InstanceTab.tsx:21
• apps/web/src/components/gastown/BeadBoard.tsx:44
• apps/web/src/app/(app)/wasteland/by-id/[wastelandId]/wanted/WantedBoardClient.tsx:42
• apps/web/src/app/admin/components/OrganizationTableBody.tsx:32

Acceptance criteria

• Product surfaces use six-role surface ladder and semantic foreground/border utilities.
• Cloud, VS Code, CLI, Slack, Agent Manager, success, warning, and destructive states follow fixed domain mappings.
• Terminal/code/diff surfaces use dedicated tokens.
• Inline links use text-link; primary yellow is not used as body/link text.
• No component-local OKLCH, raw black/white surface, emerald, amber, zinc, sky, or decorative status color remains in audited scope.
• Status remains understandable through text or icon cues, not color alone.