Add multi-viewer RDP/VNC, ollama detection, opencode config injection

[DimmKirr]

Changes

• feat(rdp): add --fullscreen, --viewer flags with FreeRDP/Royal TSX/macOS support
• feat(vnc): add --viewer flag with Royal TSX/TigerVNC/Screen Sharing dispatch
• feat(models): add cell models command showing ollama models ranked by SWE-bench
• feat(opencode): inject OPENCODE_CONFIG_CONTENT env with provider/permission config
• feat(cfg): add [models] section to devcell.toml with provider declarations
• feat(init): auto-detect ollama models during scaffold and generate TOML snippet
• feat(ollama): add ollama detection, model ranking, HuggingFace lookup, hardware check
• feat(ollama): add SWE-bench score fetching and model matching
• feat(rdp): add cert fingerprint verification for FreeRDP connections
• refactor(runner): add ExtraEnv to RunSpec for command-specific env injection
• refactor(scaffold): accept modelsSnippet param for detected ollama models
• refactor(opencode): replace file-based opencode.json with env-injected config
• refactor(runAgent): add extraEnv parameter to all agent commands
• fix(root): add SilenceUsage to prevent usage dump on handled errors
• fix(runner): change default base image from base-local to latest-base (remote)
• chore(nix/desktop): move xrdp cert to /etc/devcell/xrdp for persistence
• chore(nix/desktop): add -nevershared to x11vnc, fix syslog config
• chore(ci): restrict site deploy to main branch only
• chore(.gitignore): add .worktrees
• test(rdp): add FreeRDP client selection, cert fingerprint, Royal TSX tests
• test(vnc): add Royal TSX VNC URL test
• test(opencode): rewrite tests for env-injected config with provider support
• test(models): add CLI tests for models command
• test(cfg): add models section parsing and merge tests
• test(scaffold): add models snippet injection tests
• test(behavior): add xrdp cert volume mount and DEVCELL_DEBUG env tests
• test(ollama): add comprehensive unit tests for all ollama subpackages