Fixes for M-02 to M-14, G-01 to G-14, K-02 to K-04, X-04 to X-14, not yet reviewed

Committed before review so Windows and WSL builds can start.
Each fix was tested and mutation-checked here; the codex review
of each item is still to come, so tasks/BUGS.md stays unticked.

M-02 is mid-review: round 1 findings are fixed (apps/ely-mark/src/tally.rs).
K-01 stays deferred. The ElyMark window test mark-outside.sh failed
once at its crash-recovery step in the last run; not yet looked into.

apps/ely-tree/src/recover.rs

@@ -48,6 +48,9 @@ impl Moved {
 const KEEP: usize = 200;
 
 pub fn reflog(git: &Git, root: &Path) -> io::Result<Vec<Moved>> {
+    if !git.born(root)? {
+        return Ok(Vec::new());
+    }
     // With a date mode, `%gd` carries when HEAD moved.
     let format = "--format=%H%x00%gd%x00%gs";
     let count = format!("-n{KEEP}");