feat(editor): add explicit macOS clipboard commands

ARCHITECTURE.md

@@ -220,7 +220,11 @@ There is no retry loop for ordinary editor commands.
 Stable file reads retry up to three times, and temporary-file creation tries up to 128 random names.
 
 The main UI path is synchronous.
-The only runtime background work is the terminal-disconnect monitor thread.
+The only persistent runtime background work is the terminal-disconnect monitor thread.
+Explicit clipboard commands spawn pbcopy or pbpaste with piped input/output and an enforced UTF-8 locale.
+Nonblocking pipe I/O and child exit polling share a two-second deadline; failures kill and reap the child.
+Transfers are limited to 16 MiB, and copy checks the selected Rope byte length before materializing text.
+Clipboard paste uses the same application text path as terminal paste, including single-line prompt conversion.
 Tree-sitter work is bounded by visible ranges, read-ahead windows, per-line character limits, and a small checkpoint cache for Rust and Markdown.
 The retained renderer rejects terminal sizes above 1,000,000 cells, which turns an uncontrolled allocation into a recoverable render error followed by terminal cleanup.
 

README.md

@@ -128,6 +128,8 @@ It includes shared prompts for commands and buffer navigation, a directory picke
 | `C-k` | Cut to the end of the line |
 | `C-y` | Yank the newest cut |
 | `M-y` | Replace the last yank with an older cut |
+| `M-w` | Copy the active region to the macOS clipboard |
+| `C-c C-v` | Paste the macOS clipboard into the buffer or active prompt |
 | `C-/` or `C-_` | Undo the last edit |
 | `C-x u` | Undo the last edit |
 | `Command-z` | Undo the last edit |
@@ -186,6 +188,8 @@ Escape cancels the prompt; unknown names and invalid arguments report an error w
 | `delete-char`, `delete-backward-char` | Delete one grapheme | |
 | `set-mark`, `kill-region`, `kill-line`, `yank` | Select, cut, or insert cut text | |
 | `yank-pop` | Replace the last yank with an older cut | |
+| `copy-region` | Copy the region without deleting it | `clipboard-copy` |
+| `clipboard-paste` | Insert literal clipboard text | |
 | `self-insert-command <character>` | Insert one printable character | |
 | `execute-extended-command` | Open the command prompt | |
 | `help`, `help <command>` | List commands or describe one | `/help`, `/commands` |
@@ -216,6 +220,12 @@ Movement, edits, save, buffer changes, and undo/redo end yank-pop, so it cannot
 Each kill, yank, and yank-pop is one undo step.
 The ring is local to this process and does not read or write the system clipboard.
 
+Clipboard commands run only when requested, using macOS `pbcopy` and `pbpaste`.
+Copy keeps the region and buffer unchanged; clipboard paste is one literal undo step and clears the selection.
+In editable prompts, `C-c C-v` flattens line breaks and tabs without submitting the prompt.
+Clipboard commands time out after two seconds and reject transfers above 16 MiB or invalid UTF-8, leaving buffer text intact.
+Clipboard errors in a prompt remain visible until the next prompt key; the entered text is preserved.
+
 Contiguous typing and same-direction deletion undo as a group.
 A pause of at least 750 ms, movement, save, prompt entry, buffer switch, or deliberate edit starts a new group.
 Paste, indentation, kills, and yanks remain separate undo steps.

docs/issues/167-plan.md

@@ -0,0 +1,23 @@
+# Issue 167: Explicit macOS clipboard commands
+
+## Task and acceptance
+
+Add copy-region, with clipboard-copy as an alias, bound to M-w.
+Copy the active region without changing text, mark, history, or the local kill ring.
+An empty region produces a clear no-op status and does not invoke a clipboard program.
+Add clipboard-paste, bound to C-c C-v, inserting literal text as one undo edit with the same Unicode and mark rules as terminal paste.
+The clipboard shortcut also works inside editable prompts, applying the existing single-line conversion without submitting them.
+Clipboard commands cannot answer a dirty-quit confirmation.
+
+Use a small adapter with fixed /usr/bin/pbcopy and /usr/bin/pbpaste programs.
+Access the clipboard only when an explicit copy or paste command executes.
+Bound process I/O and exit waiting by a two-second deadline, avoid blocking pipe reads or writes, and reap failed or timed-out children.
+Limit one clipboard transfer to 16 MiB; report oversized data or invalid UTF-8 without editing the buffer.
+Do not include clipboard contents in failure messages.
+
+## Checks
+
+Use controlled executable adapters in automated tests, never the real clipboard.
+Test copy/no-region behavior, named aliases and keybindings, literal paste and undo, prompt conversion, mark and kill-ring preservation, process failures, invalid UTF-8, oversized data, and timeout cleanup.
+Run formatting, strict Clippy, the full suite, release build, independent review, and a terminal copy/paste/edit/undo/save/quit session with shell restoration.
+If manual testing changes the system clipboard, save and restore its prior bytes without displaying them.

docs/roadmap.md

@@ -112,18 +112,18 @@ Shipped:
 - Find file.
 - Switch buffer.
 - Command registry and `M-x` with prefix completion.
+- Kill ring and yank-pop.
 
 Planned:
 - Incremental search.
-- Kill ring and yank-pop.
 
 Tracking issues:
 - [closed] [#27 Add undo and redo](https://github.com/owainlewis/cortex/issues/27)
 - [closed] [#28 Add minibuffer foundation](https://github.com/owainlewis/cortex/issues/28)
 - [open] [#29 Add incremental search](https://github.com/owainlewis/cortex/issues/29)
 - [closed] [#30 Add multiple buffers, find-file, and switch-buffer](https://github.com/owainlewis/cortex/issues/30)
 - [closed] [#46 Add command registry and M-x](https://github.com/owainlewis/cortex/issues/46)
-- [open] [#47 Replace cut slot with a real kill ring](https://github.com/owainlewis/cortex/issues/47)
+- [closed] [#47 Replace cut slot with a real kill ring](https://github.com/owainlewis/cortex/issues/47)
 
 Release notes should focus on editing safety, search, and buffer navigation.
 
@@ -141,7 +141,7 @@ Delivery order:
 - [closed] [#164 Add typing and region indentation](https://github.com/owainlewis/cortex/issues/164)
 - [closed] [#165 Handle literal terminal paste](https://github.com/owainlewis/cortex/issues/165)
 - [closed] [#166 Group typing and deletion undo steps](https://github.com/owainlewis/cortex/issues/166)
-- [open] [#47 Add kill ring and yank-pop](https://github.com/owainlewis/cortex/issues/47)
+- [closed] [#47 Add kill ring and yank-pop](https://github.com/owainlewis/cortex/issues/47)
 - [open] [#167 Add explicit macOS clipboard commands](https://github.com/owainlewis/cortex/issues/167)
 - [open] [#168 Add word, page, and line navigation](https://github.com/owainlewis/cortex/issues/168)
 - [open] [#29 Add incremental search](https://github.com/owainlewis/cortex/issues/29)