docs: move tmux documentation to its own file

2 files changed, 169 insertions, 153 deletions

diff --git a/internal/textutil/textutil.go b/internal/textutil/textutil.go
index 7ef2680..1e9da3c 100644
--- a/internal/textutil/textutil.go
+++ b/internal/textutil/textutil.go
@@ -4,111 +4,125 @@ import "strings"
 
 // RenderTemplate performs simple {{var}} replacement in a template string.
 func RenderTemplate(t string, vars map[string]string) string {
-    if t == "" || len(vars) == 0 {
-        return t
-    }
-    out := t
-    for k, v := range vars {
-        out = strings.ReplaceAll(out, "{{"+k+"}}", v)
-    }
-    return out
+	if t == "" || len(vars) == 0 {
+		return t
+	}
+	out := t
+	for k, v := range vars {
+		out = strings.ReplaceAll(out, "{{"+k+"}}", v)
+	}
+	return out
 }
 
 // StripCodeFences removes surrounding Markdown triple-backtick fences.
 func StripCodeFences(s string) string {
-    t := strings.TrimSpace(s)
-    if t == "" {
-        return t
-    }
-    lines := strings.Split(t, "\n")
-    start := 0
-    for start < len(lines) && strings.TrimSpace(lines[start]) == "" {
-        start++
-    }
-    end := len(lines) - 1
-    for end >= 0 && strings.TrimSpace(lines[end]) == "" {
-        end--
-    }
-    if start >= len(lines) || end < 0 || start > end {
-        return t
-    }
-    first := strings.TrimSpace(lines[start])
-    last := strings.TrimSpace(lines[end])
-    if strings.HasPrefix(first, "```") && last == "```" && end > start {
-        inner := strings.Join(lines[start+1:end], "\n")
-        return inner
-    }
-    return t
+	t := strings.TrimSpace(s)
+	if t == "" {
+		return t
+	}
+	lines := strings.Split(t, "\n")
+	start := 0
+	for start < len(lines) && strings.TrimSpace(lines[start]) == "" {
+		start++
+	}
+	end := len(lines) - 1
+	for end >= 0 && strings.TrimSpace(lines[end]) == "" {
+		end--
+	}
+	if start >= len(lines) || end < 0 || start > end {
+		return t
+	}
+	first := strings.TrimSpace(lines[start])
+	last := strings.TrimSpace(lines[end])
+	if strings.HasPrefix(first, "```") && last == "```" && end > start {
+		inner := strings.Join(lines[start+1:end], "\n")
+		return inner
+	}
+	return t
 }
 
 // InstructionFromSelection extracts the first inline instruction and returns
 // (instruction, cleanedSelection). It detects markers on the earliest position
 // per line in precedence: strict ;text;, /* */, <!-- -->, //, #, --.
 func InstructionFromSelection(sel string) (string, string) {
-    lines := strings.Split(sel, "\n")
-    for idx, line := range lines {
-        if instr, cleaned, ok := FindFirstInstructionInLine(line); ok && strings.TrimSpace(instr) != "" {
-            lines[idx] = cleaned
-            return instr, strings.Join(lines, "\n")
-        }
-    }
-    return "", sel
+	lines := strings.Split(sel, "\n")
+	for idx, line := range lines {
+		if instr, cleaned, ok := FindFirstInstructionInLine(line); ok && strings.TrimSpace(instr) != "" {
+			lines[idx] = cleaned
+			return instr, strings.Join(lines, "\n")
+		}
+	}
+	return "", sel
 }
 
 // FindFirstInstructionInLine returns (instruction, cleaned, ok) for a single line.
 func FindFirstInstructionInLine(line string) (instr, cleaned string, ok bool) {
-    type cand struct{ start, end int; text string }
-    cands := []cand{}
-    if t, l, r, ok := FindStrictInlineTag(line); ok {
-        cands = append(cands, cand{start: l, end: r, text: t})
-    }
-    if i := strings.Index(line, "/*"); i >= 0 {
-        if j := strings.Index(line[i+2:], "*/"); j >= 0 {
-            start := i
-            end := i + 2 + j + 2
-            text := strings.TrimSpace(line[i+2 : i+2+j])
-            cands = append(cands, cand{start: start, end: end, text: text})
-        }
-    }
-    if i := strings.Index(line, "<!--"); i >= 0 {
-        if j := strings.Index(line[i+4:], "-->"); j >= 0 {
-            start := i
-            end := i + 4 + j + 3
-            text := strings.TrimSpace(line[i+4 : i+4+j])
-            cands = append(cands, cand{start: start, end: end, text: text})
-        }
-    }
-    if i := strings.Index(line, "//"); i >= 0 {
-        cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+2:])})
-    }
-    if i := strings.Index(line, "#"); i >= 0 {
-        cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+1:])})
-    }
-    if i := strings.Index(line, "--"); i >= 0 {
-        cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+2:])})
-    }
-    if len(cands) == 0 { return "", line, false }
-    best := cands[0]
-    for _, c := range cands[1:] {
-        if c.start >= 0 && (best.start < 0 || c.start < best.start) { best = c }
-    }
-    cleaned = strings.TrimRight(line[:best.start]+line[best.end:], " \t")
-    return best.text, cleaned, true
+	type cand struct {
+		start, end int
+		text       string
+	}
+	cands := []cand{}
+	if t, l, r, ok := FindStrictInlineTag(line); ok {
+		cands = append(cands, cand{start: l, end: r, text: t})
+	}
+	if i := strings.Index(line, "/*"); i >= 0 {
+		if j := strings.Index(line[i+2:], "*/"); j >= 0 {
+			start := i
+			end := i + 2 + j + 2
+			text := strings.TrimSpace(line[i+2 : i+2+j])
+			cands = append(cands, cand{start: start, end: end, text: text})
+		}
+	}
+	if i := strings.Index(line, "<!--"); i >= 0 {
+		if j := strings.Index(line[i+4:], "-->"); j >= 0 {
+			start := i
+			end := i + 4 + j + 3
+			text := strings.TrimSpace(line[i+4 : i+4+j])
+			cands = append(cands, cand{start: start, end: end, text: text})
+		}
+	}
+	if i := strings.Index(line, "//"); i >= 0 {
+		cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+2:])})
+	}
+	if i := strings.Index(line, "#"); i >= 0 {
+		cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+1:])})
+	}
+	if i := strings.Index(line, "--"); i >= 0 {
+		cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+2:])})
+	}
+	if len(cands) == 0 {
+		return "", line, false
+	}
+	best := cands[0]
+	for _, c := range cands[1:] {
+		if c.start >= 0 && (best.start < 0 || c.start < best.start) {
+			best = c
+		}
+	}
+	cleaned = strings.TrimRight(line[:best.start]+line[best.end:], " \t")
+	return best.text, cleaned, true
 }
 
 // FindStrictInlineTag finds ;text; with no spaces after/before semicolons.
 func FindStrictInlineTag(line string) (text string, left, right int, ok bool) {
-    for i := 0; i < len(line); i++ {
-        if line[i] != ';' { continue }
-        if i+1 < len(line) && line[i+1] == ' ' { continue }
-        for j := i + 1; j < len(line); j++ {
-            if line[j] == ';' {
-                if j-1 >= 0 && line[j-1] == ' ' { continue }
-                inner := strings.TrimSpace(line[i+1 : j])
-                if inner != "" { return inner, i, j + 1, true }
-            }
-        }
-    }
-    return "", -1, -1, false
+	for i := 0; i < len(line); i++ {
+		if line[i] != ';' {
+			continue
+		}
+		if i+1 < len(line) && line[i+1] == ' ' {
+			continue
+		}
+		for j := i + 1; j < len(line); j++ {
+			if line[j] == ';' {
+				if j-1 >= 0 && line[j-1] == ' ' {
+					continue
+				}
+				inner := strings.TrimSpace(line[i+1 : j])
+				if inner != "" {
+					return inner, i, j + 1, true
+				}
+			}
+		}
+	}
+	return "", -1, -1, false
 }
-
diff --git a/internal/textutil/textutil_test.go b/internal/textutil/textutil_test.go
index 3a8cd90..cfe8de8 100644
--- a/internal/textutil/textutil_test.go
+++ b/internal/textutil/textutil_test.go
@@ -1,87 +1,89 @@
 package textutil
 
 import (
-    "regexp"
-    "strings"
-    "testing"
+	"regexp"
+	"strings"
+	"testing"
 )
 
 func TestRenderTemplate_Basic(t *testing.T) {
-    out := RenderTemplate("Hello, {{name}}!", map[string]string{"name": "Hex"})
-    if out != "Hello, Hex!" {
-        t.Fatalf("render failed: %q", out)
-    }
-    // No vars
-    if RenderTemplate("x", nil) != "x" { t.Fatal("nil vars changed output") }
+	out := RenderTemplate("Hello, {{name}}!", map[string]string{"name": "Hex"})
+	if out != "Hello, Hex!" {
+		t.Fatalf("render failed: %q", out)
+	}
+	// No vars
+	if RenderTemplate("x", nil) != "x" {
+		t.Fatal("nil vars changed output")
+	}
 }
 
 func TestStripCodeFences_Variants(t *testing.T) {
-    cases := []struct{ in, want string }{
-        {"```\ncode\n```", "code"},
-        {"```go\npackage x\n```", "package x"},
-        {"no fences", "no fences"},
-        {"\n\n```\ntrim\n```\n", "trim"},
-    }
-    for _, c := range cases {
-        if got := StripCodeFences(c.in); got != c.want {
-            t.Fatalf("strip mismatch: %q != %q", got, c.want)
-        }
-    }
+	cases := []struct{ in, want string }{
+		{"```\ncode\n```", "code"},
+		{"```go\npackage x\n```", "package x"},
+		{"no fences", "no fences"},
+		{"\n\n```\ntrim\n```\n", "trim"},
+	}
+	for _, c := range cases {
+		if got := StripCodeFences(c.in); got != c.want {
+			t.Fatalf("strip mismatch: %q != %q", got, c.want)
+		}
+	}
 }
 
 func TestInstructionFromSelection_Markers(t *testing.T) {
-    inputs := []string{
-        ";do it;\ncode",
-        "/* fix */\ncode",
-        "<!-- doc -->\ncode",
-        "// change\ncode",
-        "# tweak\ncode",
-        "-- op\ncode",
-    }
-    for _, in := range inputs {
-        instr, cleaned := InstructionFromSelection(in)
-        if strings.TrimSpace(instr) == "" {
-            t.Fatalf("no instruction for input: %q", in)
-        }
-        // cleaned should not contain the instruction token
-        if strings.Contains(cleaned, instr) {
-            // Allow coincidence only if separated differently; require not exact match on same line
-            first := strings.Split(in, "\n")[0]
-            if strings.Contains(first, instr) {
-                t.Fatalf("instruction not removed: %q", cleaned)
-            }
-        }
-    }
+	inputs := []string{
+		";do it;\ncode",
+		"/* fix */\ncode",
+		"<!-- doc -->\ncode",
+		"// change\ncode",
+		"# tweak\ncode",
+		"-- op\ncode",
+	}
+	for _, in := range inputs {
+		instr, cleaned := InstructionFromSelection(in)
+		if strings.TrimSpace(instr) == "" {
+			t.Fatalf("no instruction for input: %q", in)
+		}
+		// cleaned should not contain the instruction token
+		if strings.Contains(cleaned, instr) {
+			// Allow coincidence only if separated differently; require not exact match on same line
+			first := strings.Split(in, "\n")[0]
+			if strings.Contains(first, instr) {
+				t.Fatalf("instruction not removed: %q", cleaned)
+			}
+		}
+	}
 }
 
 func TestFindFirstInstructionInLine_EarliestWins(t *testing.T) {
-    // Both markers present, earliest should win (strict tag first)
-    line := ";first;  // later"
-    instr, cleaned, ok := FindFirstInstructionInLine(line)
-    if !ok || instr != "first" {
-        t.Fatalf("expected 'first', got %q ok=%v", instr, ok)
-    }
-    if strings.Contains(cleaned, instr) {
-        t.Fatalf("expected cleaned line to remove instr: %q", cleaned)
-    }
+	// Both markers present, earliest should win (strict tag first)
+	line := ";first;  // later"
+	instr, cleaned, ok := FindFirstInstructionInLine(line)
+	if !ok || instr != "first" {
+		t.Fatalf("expected 'first', got %q ok=%v", instr, ok)
+	}
+	if strings.Contains(cleaned, instr) {
+		t.Fatalf("expected cleaned line to remove instr: %q", cleaned)
+	}
 }
 
 func TestFindStrictInlineTag(t *testing.T) {
-    if txt, l, r, ok := FindStrictInlineTag("pre;do;post"); !ok || txt != "do" || l != 3 || r != 7 {
-        t.Fatalf("strict tag parse failed: %q %d %d %v", txt, l, r, ok)
-    }
-    if _, _, _, ok := FindStrictInlineTag("; spaced ;"); ok {
-        t.Fatalf("should reject spaced strict tag")
-    }
+	if txt, l, r, ok := FindStrictInlineTag("pre;do;post"); !ok || txt != "do" || l != 3 || r != 7 {
+		t.Fatalf("strict tag parse failed: %q %d %d %v", txt, l, r, ok)
+	}
+	if _, _, _, ok := FindStrictInlineTag("; spaced ;"); ok {
+		t.Fatalf("should reject spaced strict tag")
+	}
 }
 
 // optional: ensure no ANSI codes appear in plain helpers
 func TestNoANSIInHelpers(t *testing.T) {
-    ansi := regexp.MustCompile(`\x1b\[[0-9;]*m`)
-    if ansi.MatchString(RenderTemplate("x", nil)) {
-        t.Fatalf("unexpected ansi in RenderTemplate")
-    }
-    if ansi.MatchString(StripCodeFences("x")) {
-        t.Fatalf("unexpected ansi in StripCodeFences")
-    }
+	ansi := regexp.MustCompile(`\x1b\[[0-9;]*m`)
+	if ansi.MatchString(RenderTemplate("x", nil)) {
+		t.Fatalf("unexpected ansi in RenderTemplate")
+	}
+	if ansi.MatchString(StripCodeFences("x")) {
+		t.Fatalf("unexpected ansi in StripCodeFences")
+	}
 }