Align the TUI with the web product

[nicodes]

Summary

Implements the approved TUI-only alignment plan, using the current web app as the product reference without changing web/backend behavior.

• Open on Marketplace with an adaptive sidebar: 22 columns at 120+ columns, an overlay below that, and a 100-column non-game content cap.
• Add focused keyboard navigation, Docs, unified account/local Library badges, owner/game detail pages, and UTC play-activity views.
• Separate Add, Play, Remove from Library, and Uninstall here: Add/sign-in do not download packages; Play installs missing compatible account games; existing local copies remain usable offline and are not silently overwritten.
• Add in-TUI pairing, handle/org/member management, CLI-session listing/revocation, account deletion, and revoke-then-clear sign-out with explicit confirmations and legacy-session fallback.
• Provide explicit loopback-only local pairing configuration and registry-scoped credential isolation while retaining the normal trusted pairing destination.
• Align gameplay presentation with web while preserving terminal glyph rendering, pause, pixel selection, SDK input and runtime safeguards.
• Add cancellation/stale-result, identity, authorization, layout, package-action, and session tests plus workflow documentation.

Compatibility and safety

• Existing shell-command add/remove/login/sync semantics are retained.
• Session credential ID/expiry fields are additive; legacy files remain readable.
• No web/backend source changes, database reset, dependency version updates, or release/deployment changes are included.
• The existing ANSI dependency becomes direct for safe display-cell clipping.

Verification completed locally

Toolchain: Go 1.26.2.

• Clean gofmt output and git diff --check
• go vet ./... and go vet ./sdk/...
• go test -race -count=1 -timeout 10m ./... ./sdk/...
• GOWORK=off go build ./... and GOWORK=off go vet ./...
• Cross-compilation with the release build flags for linux/amd64, linux/arm64, darwin/amd64, darwin/arm64, and windows/amd64
• Linux PTY walkthrough at 80x24 and 140x40 against the existing local API/development-auth stack: Marketplace, offline Play/pause, pairing, handle/org/member actions, owner/daily activity pages, uninstall vs membership, download-free Add, install-on-Play, session revocation, and account deletion. Disposable test accounts and files were cleaned up.

Untested scope

No production authentication was exercised. Interactive macOS/Windows/ARM terminal behavior and OS browser-launch integrations were not manually tested; cross-compilation is not interactive acceptance.

The PR is for review only; merge and deployment are not authorized by this request.

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