[v0.2] Route source mutation semantics through providers

[Teakowa]

Depends on: #142 and language-provider-protocol#1
Release coordination: #135

Goal

Prove that Wright's validated source-edit and semantic-rename architecture survives provider separation without moving generic transaction safety or transport ownership into providers.

Scope

• Preserve Wright-owned generic edit transaction semantics: source identity/version preconditions, deterministic ordering, overlap/conflict detection, atomicity, preview, and caller-controlled application.
• Route language-specific semantic decisions through LPP capabilities: semantic rename target resolution/edit generation, project-aware semantic validation, and provider-owned project semantics.
• Use the LPP conformance/mock provider for the v0.2 proof rather than creating a temporary half-cutover of opy-rs or del-rs.
• Keep ToolService/LSP/agent-facing mutation contracts source-oriented and transport-neutral.
• Ensure provider failures, unsupported capabilities, stale sources, and semantic validation failures produce structured refusals with no partial edit set.
• Add end-to-end tests for single-file/multi-file edits, collision/stale refusal, unsupported capability, and provider failure through Wright's LPP client.

Non-goals

• Production OPY or DEL provider cutover.
• New refactoring categories.
• Filesystem application inside providers.
• Exposing provider AST/HIR/WIR over LPP.
• Whole-source reconstruction as the mutation mechanism.
• Textual search/replace fallback when semantic capability is unavailable.

Acceptance criteria

• Wright obtains semantic rename/edit-validation results through LPP while retaining its existing public source-edit transaction guarantees.
• Generic stale/overlap/atomic/application policy remains Wright-owned; language-specific semantic/project validation is provider-owned.
• ToolService and LSP adapters remain free of language-specific mutation semantics.
• The conformance/mock-provider path proves the seam without OPY/DEL-specific protocol changes.
• Unsupported/missing capabilities and provider failures refuse explicitly with no partial mutation.
• The seam is directly reusable by later opy-rs and del-rs production cutovers.

[Teakowa]

Implemented by PR #152 (merged, commit d8b9d67). Semantic rename and edit validation route through LPP capabilities (lpp/rename, lpp/validateEdits, lpp/check) while Wright retains its generic edit-transaction guarantees (identity/version preconditions, deterministic ordering, overlap/conflict detection, atomicity, preview, caller-controlled application — edit.rs behaviorally unchanged, verified). Provider failures, unsupported capabilities, stale sources, and semantic validation failures produce structured atomic refusals with no partial edit set. ToolService/LSP adapters stay free of language-specific mutation semantics; the seam is reusable by opy-rs/del-rs cutovers. QA verified independently 7/7 criteria: 11 e2e + 14 unit tests, 630 workspace tests / 0 failures (605 pre-existing + 25 new), CI 12/12 green incl. lpp-client-integration. Known non-blocking gap: rename.requiresDocument has no e2e scenario until a provider implements it (documented). v0.2 acceptance criteria MET.