Sub-arc 2 of the UX arc, TUI half. When a window reserves a line-number
gutter, lines with diagnostics get a severity-colored sign glyph (E/W/I/H)
in the gutter's leading column — closing the last deferred Task #23 item.
No protocol/daemon change: the per-line severity is already frontend-side
(the diag store the DiagnosticView already reads).
- `Viewport` gains `gutter_w` so overlays can reach the gutter's leading
column at `cell_origin.col - gutter_w`; the text area is already shifted
past it, so viewport-relative painters stay gutter-agnostic.
- The gutter's number pass now runs *before* the overlays (was after), so
the DiagnosticView can draw its sign into the gutter's blanked leading
column without the number pass erasing it.
- DiagnosticView: with a gutter, draw the severity sign glyph colored by
`underline_color()`; without one, keep the legacy column-0 background
marker (the "fake gutter" that predates a real gutter column). Extracted
to `paint_line_markers` to keep `render` under the line cap.
The number never reaches column 0 (>=1 leading pad by construction), so
sign and number coexist. Diagnostic signs currently ride the line-number
gutter (visible when line numbers are on); a signs-without-numbers mode is
deferred.
Test: gutter_sign_replaces_the_column_marker_when_a_gutter_is_reserved.
Validated: fmt + clippy --all-targets clean both flavors; 1441 lib + 22
diag tests pass. Needs a TUI eyeball before the GPU half.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014TXbAwk27agwhrNNrhLi2U
Land the Model Context Protocol (MCP) integration as a transport binding,
not a built-in feature. Six Lua functions plus userdata methods expose
the substance of three MCP feature areas (resources, tools, prompts), a
notification dispatcher, and a non-trivial AI-assistance example package
that meets the architectural ship gate (spec/pmacs-spec.tex:1572): zero
direct calls into the Rust core, zero special-cased MCP handling outside
the public API, source under 2000 lines of Lua.
The M9.5 -> M9.6 -> M9.7 -> M9.8 layered composition validates the claim
"AI is a transport binding, not a feature" -- pmacs-mcp-ai composes with
pmacs-mcp-prompts.render and inherits notification handling transitively
through M9.7's package, demonstrating that the AI domain is a layer
above MCP, not a thread woven through the core.
Subtask shape:
M9.1 stdio transport + initialize handshake + restart policy
M9.2 resources with in-flight + settled cache and per-uri invalidation
M9.3 tools with isError-vs-JSON-RPC-error semantics + cancellation
M9.4 prompts with required-argument validation
M9.5 notification dispatcher (on_notification, off_notification)
M9.6 tools-as-commands fixture package + 12 audit findings disposed
M9.7 prompts-as-result-buffers fixture package + tree-sitter-md grammar
M9.8 AI-assistance fixture package (363+ LoC; 17/17 acceptance tests)
M9.9 formal package audit -- PASS on all three criteria
M9.10 release: TRANSITION-M9.md + MCP-for-package-authors guide
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Levi Neuwirth