Rebrand: Nexus Terminal → Alchementary Link

Renames the product across the codebase: Go module path, config/data
paths, keychain service name, export file extension, build tooling,
docs, and UI text. Sidebar brand mark now reads ">_ AlchementaryLink"
with "Alchementary" in the connection-group gold accent colour, and
the window title is "Alchementary Link".

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019T8bJS8BCtY5GeSG2HBj1n

internal/leviathan/parsers/asn1.go

@@ -7,7 +7,7 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/andydixon/nexus/internal/leviathan/document"
+	"github.com/andydixon/link/internal/leviathan/document"
 )
 
 // ParseASN1 produces a field tree for the DER TLV structure starting

internal/leviathan/parsers/cert.go

@@ -8,7 +8,7 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/andydixon/nexus/internal/leviathan/document"
+	"github.com/andydixon/link/internal/leviathan/document"
 )
 
 // ParseCerts scans the whole document for PEM-encoded certificates

internal/leviathan/parsers/executable.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"sort"
 
-	"github.com/andydixon/nexus/internal/leviathan/document"
+	"github.com/andydixon/link/internal/leviathan/document"
 )
 
 // ExecutableRegion is a file-backed executable code range.

internal/leviathan/parsers/formats.go

@@ -12,7 +12,7 @@ import (
 	"unicode/utf16"
 	"unicode/utf8"
 
-	"github.com/andydixon/nexus/internal/leviathan/document"
+	"github.com/andydixon/link/internal/leviathan/document"
 )
 
 // Field is one node of the parsed structure.

internal/leviathan/parsers/formats_more.go

@@ -15,7 +15,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/andydixon/nexus/internal/leviathan/document"
+	"github.com/andydixon/link/internal/leviathan/document"
 )
 
 // leaf builds a terminal Field with no children.

internal/leviathan/parsers/macho.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/andydixon/nexus/internal/leviathan/document"
+	"github.com/andydixon/link/internal/leviathan/document"
 )
 
 // Mach-O magic values (32/64, LE/BE) plus fat (universal) magic.

internal/leviathan/parsers/peimports.go

@@ -4,7 +4,7 @@ import (
 	"encoding/binary"
 	"errors"
 
-	"github.com/andydixon/nexus/internal/leviathan/document"
+	"github.com/andydixon/link/internal/leviathan/document"
 )
 
 // ImportSym is one resolved PE import (a function name, or an ordinal).