[Planning][P2] Extract SkillLite Assistant to separate repository (P3–P5)

[EXboys]

Summary

SkillLite Assistant (crates/skilllite-assistant/) currently lives in the engine monorepo with hybrid integration: subprocess bridge for chat (good) plus in-process Rust path deps on skilllite-agent, skilllite-evolution, and skilllite-sandbox (blocks clean split).

The target architecture is documented in docs/en/ASSISTANT-SPLIT-ARCHITECTURE.md. P0 (docs) and P1 (engine --json CLI surface) are largely shipped. This issue tracks the remaining phases.

Goals

Goal	Rationale
Independent release cadence	Desktop installers (dmg/msi/AppImage) vs PyPI/CLI binaries
Clear product boundary	Engine = sandbox + MCP + skilllite binary; Assistant = optional GUI
Single engine contract	Assistant talks to a released skilllite binary only
No UX regression	Streaming chat, evolution panel, Life Pulse, IDE layout preserved

Remaining phases

Phase	Scope	Exit criterion
P2 — Bridge thin	Replace remaining in-process calls in evolution_ui/*, followup_*, desktop_services	src-tauri/Cargo.toml drops skilllite-agent, skilllite-evolution, skilllite-sandbox
P3 — skilllite-client	Extract protocol types + JSON schemas (no sandbox/agent code)	Assistant depends on published crate; golden contract tests
P4 — Extract repo	Move tree to skilllite-assistant repo; stub README in engine repo	Two repos green CI
P5 — Policy	Update deny.toml; revise D1 → D1′ in architecture docs	Docs reflect implemented state

Integration model (must hold after split)

• L1 skilllite agent-rpc — streaming chat, confirm/clarify
• L2 skilllite … --json — evolution, runtime, skills list, followup
• L3 Workspace files — prompts/transcript paths (read-only where possible)

Rule: No path = "../../skilllite-*" in Assistant's Cargo.toml at target state.

Acceptance criteria

• P2: Assistant Cargo.toml has zero path deps on engine crates
• P3: skilllite-client published with protocol types + fixture tests
• P4: Separate repo with Tauri release CI + contract tests against pinned skilllite release artifact
• P5: deny.toml and ENTRYPOINTS-AND-DOMAINS.md updated to D1′ policy
• min_skilllite_version runtime check in Assistant installer/build

References

• docs/en/ASSISTANT-SPLIT-ARCHITECTURE.md
• docs/zh/ASSISTANT-SPLIT-ARCHITECTURE.md
• docs/en/ENTRYPOINTS-AND-DOMAINS.md §4 Desktop

Non-goals

• Replacing agent-rpc with terminal parsing of skilllite chat output
• Embedding the full agent loop inside Tauri
• Making Assistant a second engine entry with its own sandbox/evolution code paths