Check committed Markdown destinations

docs/roadmap/implementation.md

@@ -200,9 +200,10 @@ the parser. Code blocks and inline code supply examples rather than link nodes.
 Raw HTML destinations remain outside this Markdown-link capability. Undefined
 references rendered as ordinary text by the parser are not a new Markdown lint
 rule. Decode Markdown escapes/entities through the parser and percent escapes
-once when resolving URI path/fragment components. Ignore URI query components
-for file existence. Empty paths target the source document; an empty fragment
-selects its top. Schemed and protocol-relative URIs receive no availability
+once when resolving URI path/fragment components. Compare decoded fragments in
+lowercase to preserve PromptKit's starting convention. Ignore URI query
+components for file existence. Empty paths target the source document; an empty
+fragment selects its top. Schemed and protocol-relative URIs receive no availability
 request. Fragment checking applies to regular Markdown destinations; other
 existing files/directories receive existence checking.
 
@@ -443,6 +444,11 @@ Undefined references and HTML prose remain governed by parser interpretation.
 
 ## Stage 10: Implement internal destination and fragment checking
 
+**Completion:** Complete. The internal checker resolves committed destinations,
+checks supported fragments, preserves inspection errors, and reports distinct
+outside-checkout and submodule observations. Public selection and shared executor
+wiring remain in Stage 11.
+
 **Outcome:** Committed Markdown navigation is checked with boundary observations.
 
 1. Resolve parsed local URI components through `CandidateTree.ResolveDestination`.
@@ -456,6 +462,10 @@ Undefined references and HTML prose remain governed by parser interpretation.
 4. Reuse remediated symlink/cancellation/local-object behavior. Keep parsing,
    resolution, and rule evaluation in ordinary internal functions.
 
+**Resolution refinement:** URI query components do not participate in path
+checking. Compare fragments after one percent-decoding pass and lowercase them
+to preserve PromptKit's starting anchor matching.
+
 **Verification:** Valid/missing files and anchors, same-document/empty fragments,
 percent-escaped paths and fragments, query strings, directories and non-Markdown
 files, outside links with both settings, and submodule observations. Check how