feat: make session lifecycle and TUI resilient

[aksOps]

Summary

• make managed-session resume provider-aware and fail closed when heuristic latest-conversation behavior is ambiguous
• add responsive wide, standard, compact, and mobile-keyboard TUI layouts with truthful Running/Stopped lifecycle grouping
• group sessions by workspace, preserve safe reorder semantics, and warn when live agents share files
• restore terminal ownership after attach, add SSH-aware mouse policy, and preserve bracketed-paste bytes and control characters
• contain provider alternate-screen sequences, including aborted CSI edge cases, without clearing shell scrollback
• document session terminology, OpenCode /new, workspace sharing, terminal ownership, and Windows Terminal/PowerShell SSH limitations
• clear repository-wide static-analysis findings

Why

The dashboard previously conflated UAM-managed sessions with provider conversations, could resume a provider's latest conversation unexpectedly, and did not adapt cleanly to keyboard-constrained mobile terminals. Attach teardown could also leave overlapping terminal output, while mouse and paste behavior differed over SSH.

Compatibility

• store schema remains v3 with unknown-field preservation and no migration
• existing session names, prompt bytes, JSON list shape, provider arguments, attach keys, and default yolo behavior remain compatible
• native targets remain Linux/Ubuntu and macOS on amd64/arm64; Windows is documented as an SSH client only

Verification

• go test -race -count=1 -covermode=atomic -coverpkg=./... ./... — pass, 88.4% total coverage
• golangci-lint run ./... — 0 issues
• staticcheck ./... — pass
• go vet ./... — pass
• gosec -exclude-dir=.claude -exclude-dir=vendor ./... — 0 issues
• GOTOOLCHAIN=go1.25.12 govulncheck ./... — no called vulnerabilities
• go mod verify, gofmt, and diff cleanliness — pass
• Linux and Darwin amd64/arm64 cross-builds — pass
• GoReleaser snapshot, four archive-content checks, Linux version smoke, and SBOM generation — pass
• adversarial terminal parser review and PTY teardown race stress — pass