feat(cli): homepage landing screen for bare msdl; fix search substring bug

The bare `msdl` invocation showed all 22 products (17 consumer + 5
eval) as a flat numbered list. Replaces it with a curated landing
screen: 5 popular products (picked from real usage telemetry) plus a
2-item eval shortlist, with "list" as an escape hatch to today's full
picker and free text routed through the existing search flow.

Also fixes a search bug: querying "windows 10" incorrectly matched
Windows 11 24H2 because "10" is a substring of its build number
(26100.1742). Query words now must start at a word boundary rather
than matching anywhere, so digit fragments inside unrelated numbers
can no longer collide -- while "arm" still fuzzy-matches "ARM64".

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cli/catalog.go

@@ -60,7 +60,7 @@ func searchProducts(query string) []Product {
 		name := strings.ToLower(p.Name)
 		match := true
 		for _, w := range words {
-			if !strings.Contains(name, w) {
+			if !containsWordStart(name, w) {
 				match = false
 				break
 			}
@@ -72,6 +72,31 @@ func searchProducts(query string) []Product {
 	return results
 }
 
+// containsWordStart reports whether s contains substr starting at a word
+// boundary: the start of s, or right after a non-alphanumeric character.
+// Plain strings.Contains would let a query word match a digit fragment
+// buried inside an unrelated number -- e.g. "10" matching inside a build
+// number like "26100.1742" -- which made "windows 10" incorrectly return
+// Windows 11 24H2 results.
+func containsWordStart(s, substr string) bool {
+	from := 0
+	for {
+		i := strings.Index(s[from:], substr)
+		if i < 0 {
+			return false
+		}
+		pos := from + i
+		if pos == 0 || !isAlphanumeric(s[pos-1]) {
+			return true
+		}
+		from = pos + 1
+	}
+}
+
+func isAlphanumeric(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= '0' && b <= '9')
+}
+
 func findEvalProduct(slug string) (EvalProduct, bool) {
 	for _, p := range evalProducts {
 		if p.Slug == slug {

cli/catalog_test.go

@@ -1,6 +1,9 @@
 package main
 
-import "testing"
+import (
+	"strings"
+	"testing"
+)
 
 func TestFindProductByID_found(t *testing.T) {
 	p, ok := findProductByID("3262")
@@ -40,6 +43,35 @@ func TestSearchProducts_caseInsensitive(t *testing.T) {
 	}
 }
 
+func TestSearchProducts_noDigitFragmentCollision(t *testing.T) {
+	// "10" must not match inside the "26100.1742" build number of Windows 11
+	// 24H2/25H2 products -- regression test for the reported "windows 10"
+	// bug that returned Windows 11 results.
+	results := searchProducts("windows 10")
+	for _, p := range results {
+		if strings.Contains(p.Name, "11") {
+			t.Errorf("query %q matched %q, a Windows 11 product", "windows 10", p.Name)
+		}
+	}
+	if len(results) == 0 {
+		t.Fatal("expected windows 10 to match the actual Windows 10 products")
+	}
+}
+
+func TestSearchProducts_prefixSubstringStillWorks(t *testing.T) {
+	// "arm" should still fuzzy-match "ARM64" -- the word-boundary fix must
+	// only reject matches that start mid-digit-run, not all substrings.
+	results := searchProducts("arm")
+	if len(results) == 0 {
+		t.Fatal("expected arm to match ARM64 products")
+	}
+	for _, p := range results {
+		if !strings.Contains(strings.ToLower(p.Name), "arm") {
+			t.Errorf("unexpected match %q for query %q", p.Name, "arm")
+		}
+	}
+}
+
 func TestFindEvalProduct_found(t *testing.T) {
 	p, ok := findEvalProduct("server-2025")
 	if !ok {

cli/homepage.go

@@ -0,0 +1,114 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// homepageFeaturedIDs are the consumer products shown on the bare `msdl`
+// landing screen, picked from real usage telemetry rather than the full
+// catalog. The full catalog is still one step away via "list".
+var homepageFeaturedIDs = []string{"3262", "2618", "3321", "3113", "3265"}
+
+// homepageEvalSlugs are the eval products shown on the landing screen.
+var homepageEvalSlugs = []string{"server-2025", "win11-ent"}
+
+type homepageKind int
+
+const (
+	homepageKindProduct homepageKind = iota
+	homepageKindEval
+	homepageKindList
+	homepageKindSearch
+)
+
+type homepageChoice struct {
+	kind      homepageKind
+	productID string
+	evalSlug  string
+	query     string
+}
+
+const homepageRule = "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+
+// showHomepage prints the landing screen for a bare `msdl` invocation and
+// reads the user's choice: a number, "list" for the full catalog, or free
+// text to search by name.
+func showHomepage(latestVersion string) (homepageChoice, error) {
+	fmt.Fprintln(os.Stderr, homepageRule)
+	fmt.Fprintln(os.Stderr, "msdl — Windows ISO Downloader")
+	fmt.Fprintln(os.Stderr, "Direct links from Microsoft's CDN. No browser, no Media Creation Tool.")
+	fmt.Fprintln(os.Stderr, homepageRule)
+	fmt.Fprintln(os.Stderr)
+
+	fmt.Fprintln(os.Stderr, "Popular:")
+	featured := make([]Product, 0, len(homepageFeaturedIDs))
+	for _, id := range homepageFeaturedIDs {
+		if p, ok := findProductByID(id); ok {
+			featured = append(featured, p)
+		}
+	}
+	for i, p := range featured {
+		fmt.Fprintf(os.Stderr, "%d. %s\n", i+1, p.Name)
+	}
+	fmt.Fprintln(os.Stderr)
+
+	fmt.Fprintln(os.Stderr, "Evaluation / Enterprise:")
+	evalShortlist := make([]EvalProduct, 0, len(homepageEvalSlugs))
+	for _, slug := range homepageEvalSlugs {
+		if ep, ok := findEvalProduct(slug); ok {
+			evalShortlist = append(evalShortlist, ep)
+		}
+	}
+	for i, ep := range evalShortlist {
+		fmt.Fprintf(os.Stderr, "%d. %s\n", len(featured)+i+1, ep.Name)
+	}
+	fmt.Fprintln(os.Stderr)
+
+	fmt.Fprintln(os.Stderr, `Commands: --list (full catalog) · --help`)
+	fmt.Fprintln(os.Stderr)
+	fmt.Fprintln(os.Stderr, homepageRule)
+	if latestVersion != "" && latestVersion != Version && Version != "dev" {
+		fmt.Fprintf(os.Stderr, "Version %s  (Update Available  %s)  - a TechLatest Open-source Contribution\n", Version, latestVersion)
+	} else {
+		fmt.Fprintf(os.Stderr, "Version %s  - a TechLatest Open-source Contribution\n", Version)
+	}
+	fmt.Fprintln(os.Stderr)
+
+	max := len(featured) + len(evalShortlist)
+	fmt.Fprintf(os.Stderr, `Choice [1-%d], search by name, or "list": `, max)
+
+	scanner := bufio.NewScanner(os.Stdin)
+	if !scanner.Scan() {
+		if err := scanner.Err(); err != nil {
+			return homepageChoice{}, fmt.Errorf("reading input: %w", err)
+		}
+		return homepageChoice{}, fmt.Errorf("no input")
+	}
+	return parseHomepageInput(scanner.Text(), featured, evalShortlist)
+}
+
+// parseHomepageInput interprets the raw input line from the homepage prompt.
+func parseHomepageInput(input string, featured []Product, evalShortlist []EvalProduct) (homepageChoice, error) {
+	text := strings.TrimSpace(input)
+	if text == "" {
+		return homepageChoice{}, fmt.Errorf(`enter a choice, search term, or "list"`)
+	}
+	if strings.EqualFold(text, "list") {
+		return homepageChoice{kind: homepageKindList}, nil
+	}
+	if n, err := strconv.Atoi(text); err == nil {
+		max := len(featured) + len(evalShortlist)
+		if n < 1 || n > max {
+			return homepageChoice{}, fmt.Errorf(`enter a number between 1 and %d, a search term, or "list"`, max)
+		}
+		if n <= len(featured) {
+			return homepageChoice{kind: homepageKindProduct, productID: featured[n-1].ID}, nil
+		}
+		return homepageChoice{kind: homepageKindEval, evalSlug: evalShortlist[n-len(featured)-1].Slug}, nil
+	}
+	return homepageChoice{kind: homepageKindSearch, query: text}, nil
+}

cli/homepage_test.go

@@ -0,0 +1,166 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"strings"
+	"testing"
+)
+
+func testFeatured() []Product {
+	return []Product{
+		{ID: "3262", Name: "Windows 11 25H2 (26200.6584)"},
+		{ID: "2618", Name: "Windows 10 22H2 v1 (19045.2965)"},
+	}
+}
+
+func testEvalShortlist() []EvalProduct {
+	return []EvalProduct{
+		{Slug: "server-2025", Name: "Windows Server 2025"},
+		{Slug: "win11-ent", Name: "Windows 11 Enterprise"},
+	}
+}
+
+func TestParseHomepageInput_product(t *testing.T) {
+	choice, err := parseHomepageInput("1", testFeatured(), testEvalShortlist())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if choice.kind != homepageKindProduct || choice.productID != "3262" {
+		t.Errorf("got %+v, want product 3262", choice)
+	}
+}
+
+func TestParseHomepageInput_eval(t *testing.T) {
+	choice, err := parseHomepageInput("3", testFeatured(), testEvalShortlist())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if choice.kind != homepageKindEval || choice.evalSlug != "server-2025" {
+		t.Errorf("got %+v, want eval server-2025", choice)
+	}
+}
+
+func TestParseHomepageInput_evalSecond(t *testing.T) {
+	choice, err := parseHomepageInput("4", testFeatured(), testEvalShortlist())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if choice.kind != homepageKindEval || choice.evalSlug != "win11-ent" {
+		t.Errorf("got %+v, want eval win11-ent", choice)
+	}
+}
+
+func TestParseHomepageInput_outOfRange(t *testing.T) {
+	_, err := parseHomepageInput("5", testFeatured(), testEvalShortlist())
+	if err == nil {
+		t.Fatal("expected error for out-of-range choice")
+	}
+}
+
+func TestParseHomepageInput_listCaseInsensitive(t *testing.T) {
+	for _, s := range []string{"list", "List", "LIST"} {
+		choice, err := parseHomepageInput(s, testFeatured(), testEvalShortlist())
+		if err != nil {
+			t.Fatalf("unexpected error for %q: %v", s, err)
+		}
+		if choice.kind != homepageKindList {
+			t.Errorf("input %q: got kind %v, want list", s, choice.kind)
+		}
+	}
+}
+
+func TestParseHomepageInput_searchFallback(t *testing.T) {
+	choice, err := parseHomepageInput("windows 10", testFeatured(), testEvalShortlist())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if choice.kind != homepageKindSearch || choice.query != "windows 10" {
+		t.Errorf("got %+v, want search query \"windows 10\"", choice)
+	}
+}
+
+func TestParseHomepageInput_emptyInput(t *testing.T) {
+	_, err := parseHomepageInput("   ", testFeatured(), testEvalShortlist())
+	if err == nil {
+		t.Fatal("expected error for empty input")
+	}
+}
+
+// captureHomepage runs showHomepage with stdin/stderr redirected to pipes so
+// the rendered output and the parsed choice can both be inspected without a
+// real terminal.
+func captureHomepage(t *testing.T, stdin string, latestVersion string) (homepageChoice, string) {
+	t.Helper()
+	oldStdin, oldStderr := os.Stdin, os.Stderr
+	defer func() { os.Stdin, os.Stderr = oldStdin, oldStderr }()
+
+	inR, inW, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.Stdin = inR
+	inW.WriteString(stdin)
+	inW.Close()
+
+	outR, outW, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.Stderr = outW
+
+	choice, hpErr := showHomepage(latestVersion)
+	outW.Close()
+
+	var buf bytes.Buffer
+	io.Copy(&buf, outR)
+	if hpErr != nil {
+		t.Fatalf("unexpected error: %v", hpErr)
+	}
+	return choice, buf.String()
+}
+
+func TestShowHomepage_rendersFeaturedAndEval(t *testing.T) {
+	choice, output := captureHomepage(t, "1\n", "")
+	if choice.kind != homepageKindProduct || choice.productID != "3262" {
+		t.Errorf("got %+v, want product 3262", choice)
+	}
+	for _, want := range []string{
+		"1. Windows 11 25H2 (26200.6584)",
+		"2. Windows 10 22H2 v1 (19045.2965)",
+		"6. Windows Server 2025",
+		"7. Windows 11 Enterprise",
+		`Commands: --list (full catalog) · --help`,
+		`Choice [1-7], search by name, or "list":`,
+	} {
+		if !strings.Contains(output, want) {
+			t.Errorf("output missing %q, got:\n%s", want, output)
+		}
+	}
+}
+
+func TestShowHomepage_updateAvailableFooter(t *testing.T) {
+	oldVersion := Version
+	Version = "0.3.3"
+	defer func() { Version = oldVersion }()
+
+	_, output := captureHomepage(t, "1\n", "0.3.4")
+	if !strings.Contains(output, "Version 0.3.3  (Update Available  0.3.4)") {
+		t.Errorf("output missing update-available footer, got:\n%s", output)
+	}
+}
+
+func TestShowHomepage_noUpdateFooter(t *testing.T) {
+	oldVersion := Version
+	Version = "0.3.4"
+	defer func() { Version = oldVersion }()
+
+	_, output := captureHomepage(t, "1\n", "0.3.4")
+	if strings.Contains(output, "Update Available") {
+		t.Errorf("footer should not mention an update when already current, got:\n%s", output)
+	}
+	if !strings.Contains(output, "Version 0.3.4  - a TechLatest Open-source Contribution") {
+		t.Errorf("output missing plain version footer, got:\n%s", output)
+	}
+}

cli/main.go

@@ -46,9 +46,9 @@ func contributeURL() string {
 	return apiBaseURL() + "/contribute"
 }
 
-// printUpdateNotice checks /cli/version and prints a notice if a newer version
-// is available. Blocks up to 500ms; silently no-ops on timeout or any error.
-func printUpdateNotice() {
+// fetchLatestVersion fetches /cli/version and returns the latest version
+// string, or "" on any error or after a 500ms timeout.
+func fetchLatestVersion() string {
 	ch := make(chan string, 1)
 	go func() {
 		ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
@@ -72,11 +72,18 @@ func printUpdateNotice() {
 	}()
 	select {
 	case latest := <-ch:
-		if latest != "" && latest != Version && Version != "dev" {
-			fmt.Fprintf(os.Stderr, "\n  A new version of msdl is available: v%s\n", latest)
-			fmt.Fprintf(os.Stderr, "  Download: https://github.com/starkSV/windows-iso-downloader/releases/latest\n\n")
-		}
+		return latest
 	case <-time.After(500 * time.Millisecond):
+		return ""
+	}
+}
+
+// printUpdateNotice prints a notice if latest is newer than the running
+// binary's version.
+func printUpdateNotice(latest string) {
+	if latest != "" && latest != Version && Version != "dev" {
+		fmt.Fprintf(os.Stderr, "\n  A new version of msdl is available: v%s\n", latest)
+		fmt.Fprintf(os.Stderr, "  Download: https://github.com/starkSV/windows-iso-downloader/releases/latest\n\n")
 	}
 }
 
@@ -199,10 +206,17 @@ More info: https://msdl.tech-latest.com/cli`)
 	query := strings.Join(fs.Args(), " ")
 	noContribute := *noContributeFlag || os.Getenv("MSDL_NO_CONTRIBUTE") == "1"
 	noTelemetry := os.Getenv("MSDL_NO_TELEMETRY") == "1"
+	isHomepage := *productID == "" && !*evalMode && !*listMode && query == "" && isTerminal()
 
-	// Update check — blocks up to 500ms, then continues regardless
+	// Update check — blocks up to 500ms, then continues regardless. The
+	// homepage screen folds this into its own footer instead of printing a
+	// separate notice.
+	latest := ""
 	if !noTelemetry {
-		printUpdateNotice()
+		latest = fetchLatestVersion()
+		if !isHomepage {
+			printUpdateNotice(latest)
+		}
 	}
 
 	if *listMode {
@@ -239,20 +253,37 @@ More info: https://msdl.tech-latest.com/cli`)
 		telAction = "fetch"
 		telProductID = *productID
 		err = runConsumer(*productID, query, *langFlag, noContribute)
-	case query == "" && isTerminal():
-		// Pure interactive: combined consumer + eval picker
-		isEval, product, ep, pickErr := pickCombined()
-		if pickErr != nil {
-			return pickErr
+	case isHomepage:
+		choice, hpErr := showHomepage(latest)
+		if hpErr != nil {
+			return hpErr
 		}
-		if isEval {
-			telAction = "eval"
-			telEvalSlug = ep.Slug
-			err = runEval(ep.Slug)
-		} else {
+		switch choice.kind {
+		case homepageKindProduct:
 			telAction = "fetch"
-			telProductID = product.ID
-			err = runConsumer(product.ID, "", *langFlag, noContribute)
+			telProductID = choice.productID
+			err = runConsumer(choice.productID, "", *langFlag, noContribute)
+		case homepageKindEval:
+			telAction = "eval"
+			telEvalSlug = choice.evalSlug
+			err = runEval(choice.evalSlug)
+		case homepageKindSearch:
+			telAction = "fetch"
+			err = runConsumer("", choice.query, *langFlag, noContribute)
+		case homepageKindList:
+			isEval, product, ep, pickErr := pickCombined()
+			if pickErr != nil {
+				return pickErr
+			}
+			if isEval {
+				telAction = "eval"
+				telEvalSlug = ep.Slug
+				err = runEval(ep.Slug)
+			} else {
+				telAction = "fetch"
+				telProductID = product.ID
+				err = runConsumer(product.ID, "", *langFlag, noContribute)
+			}
 		}
 	default:
 		err = runConsumer(*productID, query, *langFlag, noContribute)