fix: improve issue ID prefix extraction for word-like suffixes

Refine ExtractIssuePrefix to better distinguish hash IDs from English
words in multi-part issue IDs. Hash suffixes now require digits or be
exactly 3 chars, preventing "test", "gate", "part" from being treated
as hashes. This fixes prefix extraction for IDs like "vc-baseline-test".

Also updates git hooks to use -q flag and adds AGENTS.md documentation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/utils/id_parser_test.go

@@ -358,9 +358,9 @@ func TestExtractIssuePrefix(t *testing.T) {
 			expected: "alpha-beta", // Last hyphen before numeric suffix
 		},
 		{
-			name:     "multi-part non-numeric suffix",
+			name:     "multi-part non-numeric suffix (word-like)",
 			issueID:  "vc-baseline-test",
-			expected: "vc-baseline", // Alphanumeric suffix uses last hyphen (GH#405 fix)
+			expected: "vc", // Word-like suffix (4+ chars, no digit) uses first hyphen (bd-fasa fix)
 		},
 		{
 			name:     "beads-vscode style prefix",

internal/utils/issue_446_test.go

@@ -43,18 +43,20 @@ func TestExtractIssuePrefixAllLetterHash(t *testing.T) {
 	}
 }
 
-// TestExtractIssuePrefixWordSuffix tests alphanumeric suffixes (GH#405 fix)
-// With the GH#405 fix, all alphanumeric suffixes use last-hyphen extraction,
-// even if they look like English words. This fixes multi-hyphen prefix parsing.
+// TestExtractIssuePrefixWordSuffix tests word-like suffixes (bd-fasa regression)
+// Word-like suffixes (4+ chars, no digits) use first-hyphen extraction because
+// they're likely multi-part IDs where everything after first hyphen is the ID.
+// This fixes bd-fasa regression where word-like suffixes were wrongly treated as hashes.
 func TestExtractIssuePrefixWordSuffix(t *testing.T) {
-	// These should use last-hyphen extraction (alphanumeric = valid issue ID suffix)
+	// Word-like suffixes (4+ chars, no digits) should use first-hyphen extraction
+	// The entire part after first hyphen is the ID, not just the last segment
 	wordSuffixes := []struct {
 		issueID  string
 		expected string
 	}{
-		{"vc-baseline-test", "vc-baseline"},  // GH#405: alphanumeric suffix uses last hyphen
-		{"vc-baseline-hello", "vc-baseline"}, // GH#405: alphanumeric suffix uses last hyphen
-		{"vc-some-feature", "vc-some"},       // GH#405: alphanumeric suffix uses last hyphen
+		{"vc-baseline-test", "vc"},  // bd-fasa: "baseline-test" is the ID, not "test"
+		{"vc-baseline-hello", "vc"}, // bd-fasa: "baseline-hello" is the ID
+		{"vc-some-feature", "vc"},   // bd-fasa: "some-feature" is the ID
 	}
 
 	for _, tc := range wordSuffixes {

internal/utils/issue_id.go

@@ -6,14 +6,18 @@ import (
 )
 
 // ExtractIssuePrefix extracts the prefix from an issue ID like "bd-123" -> "bd"
-// Uses the last hyphen before an alphanumeric suffix:
+// Uses the last hyphen before a numeric or hash-like suffix:
 //   - "beads-vscode-1" -> "beads-vscode" (numeric suffix)
-//   - "web-app-a3f8e9" -> "web-app" (hash suffix)
+//   - "web-app-a3f8e9" -> "web-app" (hash suffix with digits)
 //   - "my-cool-app-123" -> "my-cool-app" (numeric suffix)
-//   - "hacker-news-test" -> "hacker-news" (alphanumeric suffix, GH#405)
+//   - "bd-a3f" -> "bd" (3-char hash)
 //
-// Only uses first hyphen when suffix contains non-alphanumeric characters,
-// which indicates it's not an issue ID but something like a project name.
+// Falls back to first hyphen when suffix looks like an English word (4+ chars, no digits):
+//   - "vc-baseline-test" -> "vc" (word-like suffix: "test" is not a hash)
+//   - "bd-multi-part-id" -> "bd" (word-like suffix: "id" is too short but "part-id" path)
+//
+// This distinguishes hash IDs (which may contain letters but have digits or are 3 chars)
+// from multi-part IDs where the suffix after the first hyphen is the entire ID.
 func ExtractIssuePrefix(issueID string) string {
 	// Try last hyphen first (handles multi-part prefixes like "beads-vscode-1")
 	lastIdx := strings.LastIndex(issueID, "-")
@@ -33,24 +37,15 @@ func ExtractIssuePrefix(issueID string) string {
 		basePart = suffix[:dotIdx]
 	}
 
-	// Check if basePart is alphanumeric (valid issue ID suffix)
-	// Issue IDs are always alphanumeric: numeric (1, 23) or hash (a3f, xyz, test)
-	isAlphanumeric := len(basePart) > 0
-	for _, c := range basePart {
-		if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
-			isAlphanumeric = false
-			break
-		}
-	}
-
-	// If suffix is alphanumeric, this is an issue ID - use last hyphen
-	// This handles all issue ID formats including word-like hashes (GH#405)
-	if isAlphanumeric {
+	// Check if this looks like a valid issue ID suffix (numeric or hash-like)
+	// Use isLikelyHash which requires digits for 4+ char suffixes to avoid
+	// treating English words like "test", "gate", "part" as hash IDs
+	if isNumeric(basePart) || isLikelyHash(basePart) {
 		return issueID[:lastIdx]
 	}
 
-	// Suffix contains special characters - not a standard issue ID
-	// Fall back to first hyphen for cases like project names with descriptions
+	// Suffix looks like an English word (4+ chars, no digits) or contains special chars
+	// Fall back to first hyphen - the entire part after first hyphen is the ID
 	firstIdx := strings.Index(issueID, "-")
 	if firstIdx <= 0 {
 		return ""
@@ -58,6 +53,19 @@ func ExtractIssuePrefix(issueID string) string {
 	return issueID[:firstIdx]
 }
 
+// isNumeric checks if a string contains only digits
+func isNumeric(s string) bool {
+	if len(s) == 0 {
+		return false
+	}
+	for _, c := range s {
+		if c < '0' || c > '9' {
+			return false
+		}
+	}
+	return true
+}
+
 // isLikelyHash checks if a string looks like a hash ID suffix.
 // Returns true for base36 strings of 3-8 characters (0-9, a-z).
 //