[M9] Evolve structured tool API into project/session-aware service

[Teakowa]

Parent: #10

Depends on: #56

Planning status: provisional until the M8 v1 gate is complete.

Goal

Generalize the existing M4 read-only semantic service from one precompiled WIR program into a project/session-aware Wright tool API over stable public contracts.

Scope

• Accept project/source/session handles rather than requiring callers to supply internal HIR/WIR JSON.
• Expose structured compile/check/analyze/query results over the same session/driver as CLI and embedding APIs.
• Provide project/program/rule/symbol/reference/usage/CFG/finding/target metadata queries.
• Define stable request/response version and capability discovery.
• Preserve source identity across .opy and localized Workshop inputs.
• Keep transport concerns outside the service core.

Non-goals

• Direct raw arena mutation.
• Tying the service to MCP or LSP wire types.
• Reimplementing compiler/session lifecycle inside the service.

Acceptance criteria

• External tool consumers can create/load a supported session and perform structured semantic queries without internal protocol files.
• Responses are deterministic and source-aware.
• Tool API capability/version discovery allows clients to evolve safely.
• Existing M4 semantic capabilities remain available through the new project/session boundary.

[Teakowa]

Delivered in commit 03115d9 (wright_driver::service).

• ToolService::new(&mut session) accepts a driver session (not internal HIR/WIR JSON) and answers typed ToolRequests with owned ToolResponses over the same session as CLI/embedding APIs.
• Queries: project, rules, symbols, references, usage, CFG, findings, callGraph, costEstimate, targetMetadata, capabilities — all transport-neutral.
• Capability/version discovery via Capabilities (name/version/contract/operations/languages/profiles).
• Source identity preserved across .opy and Workshop inputs (project.inputIdentity + origin).