Esc alternates between the last two panes; Toggleterm is gone

Esc ran Toggleterm, which hopped between the newest DOC and the newest
TERMINAL. That distinction never earned its keep. It made Esc unpredictable —
which of three panes you landed on depended on their kinds, not on where you
had been — and it could not alternate between two files at all, which is the
case you hit most. Editing two files, Esc did nothing.

The replacement already existed. Last (SPC j j) is "the pane you were in
before this one, whichever it was": it walks the jump stack for the newest
entry naming a different pane and restores its line and column. So Esc, and
Shift-Esc in tty, now run Last, and Toggleterm is deleted rather than renamed
— a third implementation of "go to the other pane" was the thing to avoid.
SPC w t goes with it; the w group is the four directional moves, and the jump
group already had SPC j j.

Held down, Esc alternates. Two files, a file and its shell, a file and a
+Search — all the same, because Last has no notion of kind to get wrong.

This depends on the swap in the same series: Last reads the stack backwards,
and until hopping stopped appending, the pane you came from could fall off it.

windownav.snap needed only its keys and prose changed — its golden did not
move at all, which is the useful evidence here: for the one scenario the old
builtin handled well, Last produces an identical focus sequence.

Coverage for what it did not handle is new: a unit test opens a second FILE by
looking its name and asserts Esc alternates between two panes of the SAME
kind, which is the case that used to be a no-op.

Docs follow: tutor.txt, docs/helix-keys.md, docs/design.typ, and the builtin
index goldens, which are now one row shorter.

75/75 snapshots, both unit suites, and the macOS ABI build all pass.

1 files changed, 21 insertions, 21 deletions

diff --git a/test/snapshots/psearch.golden b/test/snapshots/psearch.golden
index 0ce9f2ee..25af2036 100644
--- a/test/snapshots/psearch.golden
+++ b/test/snapshots/psearch.golden
@@ -1,6 +1,6 @@
 == snap output grid=140x30 cursor=4,8
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -31,7 +31,7 @@
 |
 == snap typing grid=140x30 cursor=8,29
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -62,7 +62,7 @@
 |   /MARK
 == snap results grid=140x30 cursor=4,8
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -87,13 +87,13 @@
 |
 |
 |
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1 @p0:2:3-6 x MARK a
 |     2 @p0:4:3-6 x MARK b
 |     3 @p0:6:3-6 x MARK c
 == snap first grid=140x30 cursor=7,3
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -118,13 +118,13 @@
 |
 |
 |
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1 @p0:2:3-6 x MARK a
 |     2 @p0:4:3-6 x MARK b
 |     3 @p0:6:3-6 x MARK c
 == style first
 |0: 0-56 #949494,#121212, 57-139 d,#121212,
-|1: 0-1 #ffffff,#626262, 2-37 #949494,#121212, 38-139 d,#121212,
+|1: 0-1 #ffffff,#626262, 2-119 #949494,#121212, 120-139 d,#121212,
 |2: 0-0 d,#444444, 1-1 d,#080808, 2-139 #bdbdbd,#080808,
 |3: 0-0 d,#444444, 1-1 d,#080808, 2-3 #bdbdbd,#080808, 4-7 #080808,#80a0ff, 8-139 #bdbdbd,#080808,
 |4: 0-0 d,#444444, 1-1 d,#080808, 2-139 #bdbdbd,#080808,
@@ -149,13 +149,13 @@
 |23: 0-0 d,#444444, 1-1 d,#080808, 2-139 #bdbdbd,#080808,
 |24: 0-0 d,#444444, 1-1 d,#080808, 2-139 #bdbdbd,#080808,
 |25: 0-0 d,#444444, 1-1 d,#080808, 2-139 #bdbdbd,#080808,
-|26: 0-1 #ffffff,#262626, 2-45 #949494,#121212, 46-139 d,#121212,
+|26: 0-1 #ffffff,#262626, 2-119 #949494,#121212, 120-139 d,#121212,
 |27: 0-0 d,#444444, 1-1 d,#080808, 2-6 #626262,#080808, 7-139 #080808,#80a0ff,
 |28: 0-0 d,#444444, 1-1 d,#080808, 2-6 #626262,#080808, 7-24 #bdbdbd,#080808, 25-139 d,#080808,
 |29: 0-0 d,#121212, 1-1 d,#080808, 2-6 #626262,#080808, 7-24 #bdbdbd,#080808, 25-139 d,#080808,
 == snap second grid=140x30 cursor=7,5
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -180,13 +180,13 @@
 |
 |
 |
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1 @p0:2:3-6 x MARK a
 |     2 @p0:4:3-6 x MARK b
 |     3 @p0:6:3-6 x MARK c
 == snap back grid=140x30 cursor=7,3
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -211,13 +211,13 @@
 |
 |
 |
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1 @p0:2:3-6 x MARK a
 |     2 @p0:4:3-6 x MARK b
 |     3 @p0:6:3-6 x MARK c
 == snap nomatch grid=140x30 cursor=7,3
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -240,15 +240,15 @@
 |
 |
 |
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1 @p0:2:3-6 x MARK a
 |     2 @p0:4:3-6 x MARK b
 |     3 @p0:6:3-6 x MARK c
 == snap ttyinert grid=140x30 cursor=4,8
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|$ /tmp/pardes-snap/psearch/cwd New Del
+|$ /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |  $ printf 'x MA''RK a\nzz\nx MA''RK b\nzz\nx MA''RK c\n'
 |  x MARK a
 |  zz
@@ -271,15 +271,15 @@
 |
 |
 |
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1 @p0:2:3-6 x MARK a
 |     2 @p0:4:3-6 x MARK b
 |     3 @p0:6:3-6 x MARK c
 == snap rightsearch grid=140x30 cursor=7,5
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
-|  /tmp/pardes-snap/psearch/cwd New Del
+|  /tmp/pardes-snap/psearch/cwd                                                                                   New Del
 |
 |  x MARK a
 |  zz
@@ -302,9 +302,9 @@
 |
 |
 |
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1
-|  /tmp/pardes-snap/psearch/cwd/+Search New Del
+|  /tmp/pardes-snap/psearch/cwd/+Search                                                                           New Del
 |     1 @p0:2:3-6 x MARK a
 |     2 @p0:4:3-6 x MARK b
 |     3 @p0:6:3-6 x MARK c