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/hist.rs

@@ -95,6 +95,7 @@ fn graph(logged: &[Logged]) -> Vec<GraphRow> {
 
 impl Tree {
     pub fn set_side(&mut self, side: crate::tree::Side, cx: &mut Context<Self>) {
+        self.look = None;
         self.side = side;
         self.ensure_side(cx);
         cx.notify();
@@ -278,6 +279,7 @@ impl Tree {
 
     /// Reads a commit, or a stash with its untracked files.
     pub fn pick_in(&mut self, whose: Whose, commit: &str, cx: &mut Context<Self>) {
+        self.look = None;
         let Some(git) = self.git.as_ref().ok().cloned() else {
             return;
         };