Add panto-rsvp: RSVP reading mode for assistant text

Standalone opt-in extension that plays the latest assistant text block one
word at a time above the input, using the core mount, input-mode and
highlight("markdown") APIs settled in pantograph's rsvp-extension-plan.
Registers /rsvp; users bind it via "ctrl+s" = "/rsvp" under [keys].

Player and config logic are pure Lua with an assert-based self-check run
against a host/timer stub, since the core APIs land separately.

1 files changed, 67 insertions, 0 deletions

diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..532152a
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,67 @@
+local config = require("rsvp.config")
+local Player = require("rsvp.player").Player
+
+local function activate()
+    local panto = require("panto")
+    local ext = panto.ext
+    local settings, err = config.read(ext.config and ext.config.rsvp)
+    if not settings then error("panto-rsvp: " .. err) end
+    local uv = require("luv")
+
+    local player = Player.new {
+        settings = settings,
+        highlight = function(body) return ext.highlight(body, "markdown") end,
+        width = panto.text.width,
+        truncate = panto.text.truncate,
+        style = function() return ext.style() end,
+        new_timer = function() return uv.new_timer() end,
+        mount = function(component, placement) return ext.mount(component, placement) end,
+        input_mode = function(spec) return ext.input_mode(spec) end,
+    }
+
+    local function subscribe(name, handler)
+        ext.on(name, handler)
+    end
+
+    subscribe("session_ready", function()
+        local ok, text = pcall(function()
+            local latest
+            for _, message in ipairs(ext.agent:conversation():messages()) do
+                if message.role == "assistant" then
+                    for _, block in ipairs(message.blocks or {}) do
+                        if block.type == "text" then latest = block.text or "" end
+                    end
+                end
+            end
+            return latest or ""
+        end)
+        player:snapshot_source(ok and text or "")
+    end)
+    subscribe("render_assistant_text", function(event)
+        player:set_source(event.text or "", false, event.index)
+    end)
+    subscribe("render_assistant_text_delta", function(event)
+        if event.text ~= nil then player:update_source(event.text, false, event.index) end
+    end)
+    subscribe("render_assistant_text_complete", function(event)
+        player:update_source(event.text or "", true, event.index)
+    end)
+    subscribe("suspend", function() player:suspend() end)
+    subscribe("turn_start", function() player:cancel("turn") end)
+    subscribe("turn_interrupt", function() player:cancel("turn") end)
+    subscribe("session_end", function() player:cancel("session_end") end)
+
+    ext.register_command {
+        name = "rsvp",
+        description = "Read the latest assistant text one paragraph at a time.",
+        handler = function(arguments)
+            if arguments and arguments ~= "" then return "Usage: /rsvp" end
+            local ok, why = player:activate()
+            if not ok then
+                return "RSVP unavailable" .. (why and (": " .. tostring(why)) or "")
+            end
+        end,
+    }
+end
+
+return { name = "rsvp", activate = activate }