macos: pixel attachments, live theming, and a signed app

The AppKit shell now draws what the core renders, follows the theme without a
relaunch, and builds into something you can hand to someone.

- Pixel attachments. Surface.images was dropped on the floor here, so a PDF
  pane showed nothing at all: native_images is now set, pardes_image_s carries
  the geometry the core already clipped, and PardesView keeps one CGImage per
  (serial, page, revision) so scrolling costs a draw and not a decode. Image
  panes get real pixels instead of the petscii fallback.

- Themes take hold live. pardes_tick never advanced the chrome animation, so
  every tagline kept the previous theme's colours until the next launch and
  the 16 ms re-pump spun for the rest of the session. pardes_theme_bg retires
  the hand-agreed #121212 and drives the window background and the titlebar
  appearance; a theme with no background of its own now gets a transparent
  window over an NSVisualEffectView.

- The cell snaps to whole DEVICE pixels rather than whole points. Monaco
  advances 8.4014pt at 14, so ceiling to 9 spaced every column 7.1% wider than
  the face was drawn for.

- The dial is one notch per 10 degrees instead of 20, and a release keeps
  turning in proportion to how hard it was thrown -- ramping up from zero at
  the floor, so a slow twist coasts not a little but not at all.

- A file dropped on the grid is a click plus Look, so it opens beside the pane
  it was dropped on. No drop concept was added to the core.

- The titlebar follows the focused pane: proxy icon, filename, and the dirty
  dot. File.saved_revision is the watermark that last one needed.

- Config (SPC f c) prints the resolved startup config path.

- build.zig assembles, signs and packages the bundle itself; build-app.sh is
  gone. -Dmacos-identity= takes a Developer ID, macos-dmg makes the image, and
  the icon is Glenda.

4 files changed, 159 insertions, 155 deletions

diff --git a/test/snapshots/builtins.golden b/test/snapshots/builtins.golden
index 7e4b3366..a54b8281 100644
--- a/test/snapshots/builtins.golden
+++ b/test/snapshots/builtins.golden
@@ -100,26 +100,26 @@
 |     6 SPC c d   Delcol
 |     7 SPC c n   Newcol          topbar
 |     8 SPC d     Del
-|     9 SPC f f   Find            topbar
-|    10 SPC f g   Grep            topbar
-|    11 SPC f n   New             topbar
-|    12 SPC f s   Save
-|    13 SPC h t   Tutor           topbar
-|    14 SPC j i   Forward         C-i
-|    15 SPC j j   Last
-|    16 SPC j l   Jumplist
-|    17 SPC j o   Back            C-o
-|    18 SPC k     Kill            topbar
-|    19 SPC l D   WsDiagnostics
-|    20 SPC l S   WsSymbols
-|    21 SPC l a   CodeAction
-|    22 SPC l d   Diagnostics
-|    23 SPC l h   SelectRefs
-|    24 SPC l i   Lspinfo
-|    25 SPC l k   Hover
-|    26 SPC l r   Rename
-|    27 SPC l s   Symbols
-|    28 SPC l w   Lspwhy
+|     9 SPC f c   Config
+|    10 SPC f f   Find            topbar
+|    11 SPC f g   Grep            topbar
+|    12 SPC f n   New             topbar
+|    13 SPC f s   Save
+|    14 SPC h t   Tutor           topbar
+|    15 SPC j i   Forward         C-i
+|    16 SPC j j   Last
+|    17 SPC j l   Jumplist
+|    18 SPC j o   Back            C-o
+|    19 SPC k     Kill            topbar
+|    20 SPC l D   WsDiagnostics
+|    21 SPC l S   WsSymbols
+|    22 SPC l a   CodeAction
+|    23 SPC l d   Diagnostics
+|    24 SPC l h   SelectRefs
+|    25 SPC l i   Lspinfo
+|    26 SPC l k   Hover
+|    27 SPC l r   Rename
+|    28 SPC l s   Symbols
 == snap index-tail grid=120x60 cursor=7,58
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
 |  /tmp/pardes-snap/builtins/cwd/notes.txt                                               Save New Del
@@ -153,34 +153,34 @@
 |
 |
 |  /tmp/pardes-snap/builtins/cwd/+Help                                                        New Del
-|    25 SPC l k   Hover
-|    26 SPC l r   Rename
-|    27 SPC l s   Symbols
-|    28 SPC l w   Lspwhy
-|    29 SPC s d   Dump            topbar
-|    30 SPC s r   Restore
-|    31 SPC t a   Ascii
-|    32 SPC t b   Tagbottom
-|    33 SPC t c   Colors
-|    34 SPC t d   Debug           topbar
-|    35 SPC t i   PdfTint
-|    36 SPC t l   Palette
-|    37 SPC t n   NextColor       topbar
-|    38 SPC t p   Petscii
-|    39 SPC t r   Crt
-|    40 SPC t s   PdfSections
-|    41 SPC t t   ThemeSel
-|    42 SPC t w   Wrap
-|    43 SPC t z   PdfFit
-|    44 SPC w h   Left            C-w h, C-w left
-|    45 SPC w j   Down            C-w j, C-w down
-|    46 SPC w k   Up              C-w k, C-w up
-|    47 SPC w l   Right           C-w l, C-w right
-|    48           Look            enter, right-click
-|    49           Exec            tab, middle-click
-|    50           Theme
-|    51           Shell
-|    52
+|    26 SPC l k   Hover
+|    27 SPC l r   Rename
+|    28 SPC l s   Symbols
+|    29 SPC l w   Lspwhy
+|    30 SPC s d   Dump            topbar
+|    31 SPC s r   Restore
+|    32 SPC t a   Ascii
+|    33 SPC t b   Tagbottom
+|    34 SPC t c   Colors
+|    35 SPC t d   Debug           topbar
+|    36 SPC t i   PdfTint
+|    37 SPC t l   Palette
+|    38 SPC t n   NextColor       topbar
+|    39 SPC t p   Petscii
+|    40 SPC t r   Crt
+|    41 SPC t s   PdfSections
+|    42 SPC t t   ThemeSel
+|    43 SPC t w   Wrap
+|    44 SPC t z   PdfFit
+|    45 SPC w h   Left            C-w h, C-w left
+|    46 SPC w j   Down            C-w j, C-w down
+|    47 SPC w k   Up              C-w k, C-w up
+|    48 SPC w l   Right           C-w l, C-w right
+|    49           Look            enter, right-click
+|    50           Exec            tab, middle-click
+|    51           Theme
+|    52           Shell
+|    53
 == snap not-a-picker grid=120x60 cursor=7,58
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
 |  /tmp/pardes-snap/builtins/cwd/notes.txt                                               Save New Del
@@ -214,34 +214,34 @@
 |
 |
 |  /tmp/pardes-snap/builtins/cwd/+Help                                                        New Del
-|    25 SPC l k   Hover
-|    26 SPC l r   Rename
-|    27 SPC l s   Symbols
-|    28 SPC l w   Lspwhy
-|    29 SPC s d   Dump            topbar
-|    30 SPC s r   Restore
-|    31 SPC t a   Ascii
-|    32 SPC t b   Tagbottom
-|    33 SPC t c   Colors
-|    34 SPC t d   Debug           topbar
-|    35 SPC t i   PdfTint
-|    36 SPC t l   Palette
-|    37 SPC t n   NextColor       topbar
-|    38 SPC t p   Petscii
-|    39 SPC t r   Crt
-|    40 SPC t s   PdfSections
-|    41 SPC t t   ThemeSel
-|    42 SPC t w   Wrap
-|    43 SPC t z   PdfFit
-|    44 SPC w h   Left            C-w h, C-w left
-|    45 SPC w j   Down            C-w j, C-w down
-|    46 SPC w k   Up              C-w k, C-w up
-|    47 SPC w l   Right           C-w l, C-w right
-|    48           Look            enter, right-click
-|    49           Exec            tab, middle-click
-|    50           Theme
-|    51           Shell
-|    52
+|    26 SPC l k   Hover
+|    27 SPC l r   Rename
+|    28 SPC l s   Symbols
+|    29 SPC l w   Lspwhy
+|    30 SPC s d   Dump            topbar
+|    31 SPC s r   Restore
+|    32 SPC t a   Ascii
+|    33 SPC t b   Tagbottom
+|    34 SPC t c   Colors
+|    35 SPC t d   Debug           topbar
+|    36 SPC t i   PdfTint
+|    37 SPC t l   Palette
+|    38 SPC t n   NextColor       topbar
+|    39 SPC t p   Petscii
+|    40 SPC t r   Crt
+|    41 SPC t s   PdfSections
+|    42 SPC t t   ThemeSel
+|    43 SPC t w   Wrap
+|    44 SPC t z   PdfFit
+|    45 SPC w h   Left            C-w h, C-w left
+|    46 SPC w j   Down            C-w j, C-w down
+|    47 SPC w k   Up              C-w k, C-w up
+|    48 SPC w l   Right           C-w l, C-w right
+|    49           Look            enter, right-click
+|    50           Exec            tab, middle-click
+|    51           Theme
+|    52           Shell
+|    53
 == snap window-group grid=120x60 cursor=7,32
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
 |  /tmp/pardes-snap/builtins/cwd/notes.txt                                               Save New Del
@@ -344,23 +344,23 @@
 |     6 SPC c d   Delcol
 |     7 SPC c n   Newcol          topbar
 |     8 SPC d     Del
-|     9 SPC f f   Find            topbar
-|    10 SPC f g   Grep            topbar
-|    11 SPC f n   New             topbar
-|    12 SPC f s   Save
-|    13 SPC h t   Tutor           topbar
-|    14 SPC j i   Forward         C-i
-|    15 SPC j j   Last
-|    16 SPC j l   Jumplist
-|    17 SPC j o   Back            C-o
-|    18 SPC k     Kill            topbar
-|    19 SPC l D   WsDiagnostics
-|    20 SPC l S   WsSymbols
-|    21 SPC l a   CodeAction
-|    22 SPC l d   Diagnostics
-|    23 SPC l h   SelectRefs
-|    24 SPC l i   Lspinfo
-|    25 SPC l k   Hover
-|    26 SPC l r   Rename
-|    27 SPC l s   Symbols
-|    28 SPC l w   Lspwhy
+|     9 SPC f c   Config
+|    10 SPC f f   Find            topbar
+|    11 SPC f g   Grep            topbar
+|    12 SPC f n   New             topbar
+|    13 SPC f s   Save
+|    14 SPC h t   Tutor           topbar
+|    15 SPC j i   Forward         C-i
+|    16 SPC j j   Last
+|    17 SPC j l   Jumplist
+|    18 SPC j o   Back            C-o
+|    19 SPC k     Kill            topbar
+|    20 SPC l D   WsDiagnostics
+|    21 SPC l S   WsSymbols
+|    22 SPC l a   CodeAction
+|    23 SPC l d   Diagnostics
+|    24 SPC l h   SelectRefs
+|    25 SPC l i   Lspinfo
+|    26 SPC l k   Hover
+|    27 SPC l r   Rename
+|    28 SPC l s   Symbols
diff --git a/test/snapshots/builtins.snap b/test/snapshots/builtins.snap
index 93e33710..f6b5723b 100644
--- a/test/snapshots/builtins.snap
+++ b/test/snapshots/builtins.snap
@@ -49,12 +49,16 @@ stable 700 15000
 snap window-group
 # back to the whole index, and a NAME in it is live text like anywhere else:
 # middle-click `Tutor` and the tutor opens. That is the picking a stepping
-# picker would have done, minus running the thirty-nine rows you passed.
+# picker would have done, minus running the rows you passed.
+#
+# The one place in this suite a builtin cannot be added for free: the click is
+# a SCREEN coordinate, so every row inserted above `SPC h t` in the listing
+# moves Tutor down one and this number with it.
 key space ?
 wait 10000 SPC c n
 stable 700 15000
-press middle 20 45
-release middle 20 45
+press middle 20 46
+release middle 20 46
 wait 10000 PARDES TUTOR
 stable 700 15000
 snap tutor-from-index
diff --git a/test/snapshots/leader.golden b/test/snapshots/leader.golden
index 74719f13..d58e8d6c 100644
--- a/test/snapshots/leader.golden
+++ b/test/snapshots/leader.golden
@@ -193,16 +193,16 @@
 |     6 SPC c d   Delcol
 |     7 SPC c n   Newcol          topbar
 |     8 SPC d     Del
-|     9 SPC f f   Find            topbar
-|    10 SPC f g   Grep            topbar
-|    11 SPC f n   New             topbar
-|    12 SPC f s   Save
-|    13 SPC h t   Tutor           topbar
-|    14 SPC j i   Forward         C-i
-|    15 SPC j j   Last
-|    16 SPC j l   Jumplist
-|    17 SPC j o   Back            C-o
-|    18 SPC k     Kill            topbar
+|     9 SPC f c   Config
+|    10 SPC f f   Find            topbar
+|    11 SPC f g   Grep            topbar
+|    12 SPC f n   New             topbar
+|    13 SPC f s   Save
+|    14 SPC h t   Tutor           topbar
+|    15 SPC j i   Forward         C-i
+|    16 SPC j j   Last
+|    17 SPC j l   Jumplist
+|    18 SPC j o   Back            C-o
 == snap help-group grid=100x40 cursor=7,22
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
 |  /tmp/pardes-snap/leader/cwd/cmds.txt                              Save New Del
@@ -357,16 +357,16 @@
 |     6 SPC c d   Delcol
 |     7 SPC c n   Newcol          topbar
 |     8 SPC d     Del
-|     9 SPC f f   Find            topbar
-|    10 SPC f g   Grep            topbar
-|    11 SPC f n   New             topbar
-|    12 SPC f s   Save
-|    13 SPC h t   Tutor           topbar
-|    14 SPC j i   Forward         C-i
-|    15 SPC j j   Last
-|    16 SPC j l   Jumplist
-|    17 SPC j o   Back            C-o
-|    18 SPC k     Kill            topbar
+|     9 SPC f c   Config
+|    10 SPC f f   Find            topbar
+|    11 SPC f g   Grep            topbar
+|    12 SPC f n   New             topbar
+|    13 SPC f s   Save
+|    14 SPC h t   Tutor           topbar
+|    15 SPC j i   Forward         C-i
+|    16 SPC j j   Last
+|    17 SPC j l   Jumplist
+|    18 SPC j o   Back            C-o
 == snap help-toggles grid=100x40 cursor=7,22
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
 |  /tmp/pardes-snap/leader/cwd/cmds.txt                              Save New Del
diff --git a/test/snapshots/ttyhelp.golden b/test/snapshots/ttyhelp.golden
index 69b5961a..a580263b 100644
--- a/test/snapshots/ttyhelp.golden
+++ b/test/snapshots/ttyhelp.golden
@@ -42,24 +42,24 @@
 |     6 SPC c d   Delcol
 |     7 SPC c n   Newcol          topbar
 |     8 SPC d     Del
-|     9 SPC f f   Find            topbar
-|    10 SPC f g   Grep            topbar
-|    11 SPC f n   New             topbar
-|    12 SPC f s   Save
-|    13 SPC h t   Tutor           topbar
-|    14 SPC j i   Forward         C-i
-|    15 SPC j j   Last
-|    16 SPC j l   Jumplist
-|    17 SPC j o   Back            C-o
-|    18 SPC k     Kill            topbar
-|    19 SPC l D   WsDiagnostics
-|    20 SPC l S   WsSymbols
-|    21 SPC l a   CodeAction
-|    22 SPC l d   Diagnostics
-|    23 SPC l h   SelectRefs
-|    24 SPC l i   Lspinfo
-|    25 SPC l k   Hover
-|    26 SPC l r   Rename
+|     9 SPC f c   Config
+|    10 SPC f f   Find            topbar
+|    11 SPC f g   Grep            topbar
+|    12 SPC f n   New             topbar
+|    13 SPC f s   Save
+|    14 SPC h t   Tutor           topbar
+|    15 SPC j i   Forward         C-i
+|    16 SPC j j   Last
+|    17 SPC j l   Jumplist
+|    18 SPC j o   Back            C-o
+|    19 SPC k     Kill            topbar
+|    20 SPC l D   WsDiagnostics
+|    21 SPC l S   WsSymbols
+|    22 SPC l a   CodeAction
+|    23 SPC l d   Diagnostics
+|    24 SPC l h   SelectRefs
+|    25 SPC l i   Lspinfo
+|    26 SPC l k   Hover
 == snap leaderworks grid=100x30 cursor=7,4
 |New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
 |$ /tmp/pardes-snap/ttyhelp/cwd                                           New Del
@@ -73,21 +73,21 @@
 |     6 SPC c d   Delcol
 |     7 SPC c n   Newcol          topbar
 |     8 SPC d     Del
-|     9 SPC f f   Find            topbar
-|    10 SPC f g   Grep            topbar
-|    11 SPC f n   New             topbar
-|    12 SPC f s   Save
-|    13 SPC h t   Tutor           topbar
-|    14 SPC j i   Forward         C-i
-|    15 SPC j j   Last
-|    16 SPC j l   Jumplist
-|    17 SPC j o   Back            C-o
-|    18 SPC k     Kill            topbar
-|    19 SPC l D   WsDiagnostics
-|    20 SPC l S   WsSymbols
-|    21 SPC l a   CodeAction
-|    22 SPC l d   Diagnostics
-|    23 SPC l h   SelectRefs
-|    24 SPC l i   Lspinfo
-|    25 SPC l k   Hover
-|    26 SPC l r   Rename
+|     9 SPC f c   Config
+|    10 SPC f f   Find            topbar
+|    11 SPC f g   Grep            topbar
+|    12 SPC f n   New             topbar
+|    13 SPC f s   Save
+|    14 SPC h t   Tutor           topbar
+|    15 SPC j i   Forward         C-i
+|    16 SPC j j   Last
+|    17 SPC j l   Jumplist
+|    18 SPC j o   Back            C-o
+|    19 SPC k     Kill            topbar
+|    20 SPC l D   WsDiagnostics
+|    21 SPC l S   WsSymbols
+|    22 SPC l a   CodeAction
+|    23 SPC l d   Diagnostics
+|    24 SPC l h   SelectRefs
+|    25 SPC l i   Lspinfo
+|    26 SPC l k   Hover