Remove stale phase/spec references from code comments

Strip "Phase N", "SPEC §X.Y", and "v1.x" planning labels from comments
across the Rust crates and editor layers now that those tracking
artifacts are gone. Comments only — no logic, strings, or test names
touched.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

crates/nuwiki-lsp/tests/navigation.rs

@@ -1,7 +1,7 @@
-//! Tests for the Phase 8 navigation pieces: WorkspaceIndex queries,
+//! Tests for the navigation pieces: WorkspaceIndex queries,
 //! page-name derivation, anchor slugify, position lookup, and link
 //! resolution. The async LSP handlers are exercised through these
-//! helpers; end-to-end JSON-RPC drive lives in a follow-up phase.
+//! helpers; end-to-end JSON-RPC drive lives elsewhere.
 
 use std::path::PathBuf;