Validate Zed Link Navigation

Goal

Prove that a locally installed Zed extension can start a preinstalled matching forma binary and provide editor-native navigation for Forma-controlled Markdown.

In Scope

• Add a minimal Rust/WASM Zed extension under extensions/zed/.
• Register forma lsp for built-in Markdown.
• Find forma through the Zed worktree environment.
• Validate Definition and DocumentLink in examples/getting-started-workspace/.
• Correct wikilink and embed target styling through theme-derived semantic tokens.
• Record protocol, latency, idle-resource, invalidation, and restart behavior.

Out Of Scope

• CLI acquisition or update UX.
• Registry publication.
• Preview, panels, workspace status, completion, backlinks, or write operations.

Acceptance Criteria

• Zed starts forma lsp from the worktree environment and reports an actionable error when the binary is absent.
• A relative Markdown link, wikilink, aliased wikilink, fragment, and embed navigate to canonical Markdown source.
• Multiple schema-declared owner values each have the correct range and target.
• A normal string containing the same text is not treated as a reference.
• Unresolved references do not open an arbitrary file, and ambiguous references return candidates.
• Unsaved source changes participate in navigation.
• Configuration and controlled-scope changes refresh safely, and Zed recovers after the server exits.
• Zed protocol logs contain no material errors and the measured navigation budgets pass.
• Wikilink and embed targets no longer inherit Markdown emphasis styling when semantic tokens are enabled, while alias text remains theme-native.
• No Preview, CLI management, registry publication, or duplicated Core semantics are introduced.

Current Validation State

This completed task records the Alpha 17/18 validation boundary. Its semantic-token styling evidence is historical: the accepted post-validation direction removes Forma styling from the LSP and leaves Markdown source highlighting entirely to Zed while retaining navigation behavior.

Automated protocol, semantic-token, fixture, WASM build, invalidation, restart, and performance checks pass. The Dev Extension remains intentionally unpublished and requires a matching preinstalled forma from the worktree environment.

Real Zed interaction also passes: Markdown links, fragments, wikilinks, aliases, embeds, multi-owner frontmatter, inert values, unsaved overlays, unresolved references, ambiguity candidates, language-server restart, and full editor restart were exercised against the getting-started workspace. Markdown combined semantic tokens produce theme-aligned target styling without replacing Zed's native Markdown grammar. Evidence and residual Zed constraints are recorded in discovery/forma-lsp-zed-navigation-validation-2026-07-13.