Merge branch 'buffer-implementation'HEADmain

Establishes the first working baseline: moji <file> opens a file into a
ropey rope and edits it with Helix selection-first modal editing, under a
DO-178C DAL-C requirements and traceability process.

Prior to this, main tracked four files and src/main.rs was still
println!("Hello, world!") — there was no buildable state to build on.

Verified on a fresh clone of the branch with no untracked files:
cargo build; clippy --all-targets -D warnings clean; 294 tests passing;
scripts/check-trace.sh reports 98/98 requirements traced in both
directions.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/.config/config.toml b/.config/config.toml
new file mode 100644
index 0000000..8520772
--- /dev/null
+++ b/.config/config.toml
@@ -0,0 +1,151 @@
+# mojibake configuration.
+#
+# This file is both the runtime configuration and, via `include_str!` in
+# src/config.rs, the compiled-in default set. User settings in
+# $MOJIBAKE_CONFIG/config.toml override these per individual binding;
+# anything not listed here keeps its default. (MJB-LLR-180, MJB-LLR-182)
+#
+# Key syntax: "<k>" for one key, "<g><g>" for a sequence, with the modifier
+# prefixes ctrl-, alt-, shift-, e.g. "<ctrl-d>".
+#
+# Bindings follow the Helix default keymap: https://docs.helix-editor.com/keymap.html
+
+# Editor settings live in their own table rather than at top level: the
+# top-level struct uses `#[serde(flatten)]` for the data/config directories,
+# and config-rs stringifies values it buffers through a flattened map, which
+# breaks integer and boolean fields. (MJB-LLR-185)
+[editor]
+# Lines of context kept between the cursor and the viewport edge.
+# Clamped to half the viewport height at use. (MJB-LLR-093)
+scrolloff = 5
+
+# Append a trailing newline on write when the buffer lacks one.
+insert_final_newline = true
+
+# Consulted by App before any component sees the key. A match here is consumed
+# and never reaches the buffer, so these fire in every mode. (MJB-LLR-203)
+[keybindings.global]
+"<ctrl-c>" = "Quit"
+"<ctrl-z>" = "Suspend"
+
+[keybindings.normal]
+# Movement (MJB-HLR-006)
+"<h>" = "MoveCharLeft"
+"<j>" = "MoveLineDown"
+"<k>" = "MoveLineUp"
+"<l>" = "MoveCharRight"
+"<left>" = "MoveCharLeft"
+"<down>" = "MoveLineDown"
+"<up>" = "MoveLineUp"
+"<right>" = "MoveCharRight"
+
+# Word motions. These leave a SELECTION, not a bare cursor. (MJB-HLR-007)
+"<w>" = "MoveNextWordStart"
+"<b>" = "MovePrevWordStart"
+"<e>" = "MoveNextWordEnd"
+"<W>" = "MoveNextLongWordStart"
+"<B>" = "MovePrevLongWordStart"
+"<E>" = "MoveNextLongWordEnd"
+
+# Goto mode (MJB-HLR-008)
+"<g><g>" = "GotoFileStart"
+"<g><e>" = "GotoLastLine"
+"<g><h>" = "GotoLineStart"
+"<g><l>" = "GotoLineEnd"
+"<g><s>" = "GotoFirstNonWhitespace"
+
+# Selection manipulation
+"<x>" = "ExtendLineBelow"
+"<;>" = "CollapseSelection"
+"<alt-;>" = "FlipSelections"
+"<%>" = "SelectAll"
+"<v>" = "SelectMode"
+
+# Entering insert mode (MJB-HLR-009)
+"<i>" = "InsertMode"
+"<a>" = "AppendMode"
+"<I>" = "InsertAtLineStart"
+"<A>" = "InsertAtLineEnd"
+"<o>" = "OpenBelow"
+"<O>" = "OpenAbove"
+
+# Modification (MJB-HLR-010)
+"<d>" = "DeleteSelection"
+"<c>" = "ChangeSelection"
+
+# Undo / redo (MJB-HLR-011)
+"<u>" = "Undo"
+"<U>" = "Redo"
+
+# Scrolling and paging (MJB-HLR-013)
+"<ctrl-u>" = "PageCursorHalfUp"
+"<ctrl-d>" = "PageCursorHalfDown"
+"<ctrl-b>" = "PageUp"
+"<ctrl-f>" = "PageDown"
+"<pageup>" = "PageUp"
+"<pagedown>" = "PageDown"
+
+# Command mode (MJB-HLR-016)
+"<:>" = "CommandMode"
+
+[keybindings.select]
+# Select mode repeats normal-mode motions, but extends rather than replaces.
+"<h>" = "ExtendCharLeft"
+"<j>" = "ExtendLineDown"
+"<k>" = "ExtendLineUp"
+"<l>" = "ExtendCharRight"
+"<w>" = "ExtendNextWordStart"
+"<b>" = "ExtendPrevWordStart"
+"<e>" = "ExtendNextWordEnd"
+"<esc>" = "NormalMode"
+"<v>" = "NormalMode"
+"<d>" = "DeleteSelection"
+"<c>" = "ChangeSelection"
+"<;>" = "CollapseSelection"
+
+[keybindings.insert]
+# Any printable key not bound here self-inserts; that fallback is not
+# expressible as a table entry. (MJB-LLR-156)
+"<esc>" = "NormalMode"
+"<enter>" = "InsertNewline"
+"<backspace>" = "DeleteCharBackward"
+"<delete>" = "DeleteCharForward"
+"<tab>" = "InsertTab"
+"<ctrl-h>" = "DeleteCharBackward"
+"<ctrl-d>" = "DeleteCharForward"
+"<ctrl-w>" = "DeleteWordBackward"
+"<ctrl-u>" = "KillToLineStart"
+"<left>" = "MoveCharLeft"
+"<down>" = "MoveLineDown"
+"<up>" = "MoveLineUp"
+"<right>" = "MoveCharRight"
+
+[keybindings.command]
+# Command mode routes keys to a line editor; only these are bound. (MJB-LLR-158)
+"<esc>" = "NormalMode"
+"<enter>" = "CommandSubmit"
+"<backspace>" = "CommandBackspace"
+
+[styles.normal]
+cursor = "black on white"
+selection = "on blue"
+linenr = "gray8"
+statusline = "black on cyan"
+
+[styles.insert]
+cursor = "black on green"
+selection = "on blue"
+linenr = "gray8"
+statusline = "black on green"
+
+[styles.select]
+cursor = "black on white"
+selection = "on magenta"
+linenr = "gray8"
+statusline = "black on magenta"
+
+[styles.command]
+cursor = "black on white"
+selection = "on blue"
+linenr = "gray8"
+statusline = "black on yellow"