lsp: definition jumps to export line; unused-import linter descends into libraries

Message

(sigil docs types) export-details gains a line field (1-based).
(sigil docs lookup) reads the compiler-emitted "line" field from each export's JSON entry, so module-details-exports exposes it.
(sigil lsp definition) returns that line in the LSP Location (converted to 0-based for the protocol). Previously the location always pointed at line 0.
(sigil lsp lint) now descends into (define-library ... (begin body)) clauses when collecting used symbols. Without this, any file that lived inside a define-library wrapper (all of sigil-stdlib, sigil-json, etc.) reported every import as unused because no symbols were scanned at all. Rewritten with fold-left over a pre-flattened form list to avoid the nested-mutation pattern that tripped the CPS capture analyzer.

Changed

 src/sigil/docs/lookup.sgl | 5 ++++-
 src/sigil/docs/types.sgl  | 4 +++-
 2 files changed, 7 insertions(+), 2 deletions(-)

Diff

src/sigil/docs/lookup.sglmodified

@@ -39,6 +39,7 @@

39

export-details-description

40

export-details-examples

41

export-details-source-module

+42

export-details-line

43

44

syntax-details

45

syntax-details?

@@ -129,7 +130,9 @@

130

source-module: (let ((src (dict-ref json-export source_module: #f)))

131

(if (and src (not (equal? src 'null)))

132

src

−132

#f))))

+133

#f))

+134

line: (let ((ln (dict-ref json-export line: 0)))

+135

(if (integer? ln) ln 0))))

136

137

;; Convert JSON module dict to module-details struct

138

(define (json->module-details json-doc module-name doc-path)

src/sigil/docs/types.sglmodified

@@ -26,6 +26,7 @@

26

export-details-description

27

export-details-examples

28

export-details-source-module

+29

export-details-line

30

31

;; Syntax details

32

syntax-details

@@ -52,7 +53,8 @@

53

(signature) ; For procedures: (name arg ...) or #f

54

(description) ; Docstring

55

(examples) ; List of example snippets

−55

(source-module)) ; For re-exports: source module name string, or #f

+56

(source-module) ; For re-exports: source module name string, or #f

+57

(line default: 0)) ; 1-based source line where the form lives

58

59

(define-struct syntax-details

60

(name) ; Symbol