infocmp -C: high-byte octal escaping + inline %r placement

Two derivable termcap fixes (clean-room, oracle-verified):
- termcap value escaping now renders high bytes 0x81..0xff as 3-digit octal (\nnn),
  matching ncurses (e.g. CSI 0x9b -> \233); previously emitted raw.
- %r (reverse the two parameters) is emitted INLINE before the first
  parameter-consuming output op, not prepended: \E&a%p2%dc%p1%dY -> \E&a%r%dc%dY
  (was %r\E&a%dc%dY).

Termcap (-C) content match 25.1% -> 27.7%, exact 16.3% -> 18.1% across the DB.
Remaining derivable work continues (control-char octal/caret islong rule, the
as/ae/rs drop conditions, the wrap rule); the me/sgr0 derivation is honestly bounded
as not a function of observable inputs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CbiPgWC3PHKmrTNvZzXcWQ

Author: claude

crates/ncurses-tools/src/bin/infocmp.rs

@@ -224,6 +224,7 @@ fn tc_escape_byte(out: &mut String, b: u8) {
             out.push('^');
             out.push((b ^ 0x40) as char);
         }
+        0x81..=0xff => out.push_str(&format!("\\{b:03o}")),
         _ => out.push(b as char),
     }
 }
@@ -288,9 +289,9 @@ fn try_translate(v: &[u8]) -> Option<String> {
     };
 
     let mut out = String::new();
-    if reverse {
-        out.push_str("%r");
-    }
+    // `%r` (reverse the two parameters) is emitted inline, just before the first parameter-consuming
+    // output op (not prepended) -- e.g. `\E&a%p2%dc%p1%dY` -> `\E&a%r%dc%dY`.
+    let mut r_pending = reverse;
     let mut i = 0;
     while i < v.len() {
         if v[i] != b'%' {
@@ -309,10 +310,18 @@ fn try_translate(v: &[u8]) -> Option<String> {
             }
             Some(b'p') => i += 3, // `%pN` push -- the following format op produces the output
             Some(b'd') => {
+                if r_pending {
+                    out.push_str("%r");
+                    r_pending = false;
+                }
                 out.push_str("%d");
                 i += 2;
             }
             Some(b'c') => {
+                if r_pending {
+                    out.push_str("%r");
+                    r_pending = false;
+                }
                 out.push_str("%.");
                 i += 2;
             }
@@ -328,6 +337,10 @@ fn try_translate(v: &[u8]) -> Option<String> {
                 if !(2..=9).contains(&width) {
                     return None;
                 }
+                if r_pending {
+                    out.push_str("%r");
+                    r_pending = false;
+                }
                 out.push('%');
                 out.push((b'0' + width as u8) as char);
                 i = j + 1;
@@ -339,6 +352,10 @@ fn try_translate(v: &[u8]) -> Option<String> {
                     && v.get(i + 6) == Some(&b'%')
                     && v.get(i + 7) == Some(&b'c') =>
             {
+                if r_pending {
+                    out.push_str("%r");
+                    r_pending = false;
+                }
                 out.push_str("%+");
                 tc_escape_byte(&mut out, v[i + 2]);
                 i += 8;