feat(ui): ralpi-style chat progress and pipeline-overview footer

phases.ts becomes a live chat widget (spinner + tool-call tree) and the
check-runner posts per-agent tool-call summaries and an expandable
completion tree through a custom message renderer; footer.ts adds the
static pipeline-overview status strip for single checks and /pygienium-all.

src/commands.ts

@@ -9,10 +9,7 @@
  * @module pygienium/commands
  */
 
-import type {
-	ExtensionCommandContext,
-	ExtensionUIContext,
-} from "@earendil-works/pi-coding-agent";
+import type { ExtensionCommandContext } from "@earendil-works/pi-coding-agent";
 import { resolve } from "node:path";
 import {
 	getAllChecks,
@@ -20,6 +17,9 @@ import {
 	type CheckDefinition,
 } from "./checks/registry.js";
 import { runCheck, parseCheckArgs } from "./modes/check-runner.js";
+import {
+	runCheck,
+	parseCheckArgs,
 import { parseAllArgs, runAllChecks, allSummaryPath } from "./modes/all.js";
 import { buildPygieniumHelpLines } from "./help.js";
 import {
@@ -38,12 +38,16 @@ import {
 	exportBundlePath,
 	type ExportFilters,
 } from "./export.js";
+import type { SendChatMessage } from "./phases.js";
 
 /** Narrow context slice handlers need (a subset of `ExtensionCommandContext`). */
 export type PygieniumCtx = Pick<
 	ExtensionCommandContext,
 	"cwd" | "mode" | "hasUI" | "ui"
->;
+> & {
+	/** Optional callback to post messages to the chat window. */
+	sendChatMessage?: SendChatMessage;
+};
 
 function print(ctx: PygieniumCtx, line: string): void {
 	// In TUI mode, also surface the first line as a notification.
@@ -162,6 +166,7 @@ export async function handleAllCommand(
 		only: parsed.only,
 		ui: ctx.ui,
 		hasUI: ctx.hasUI,
+		sendChatMessage: ctx.sendChatMessage,
 	});
 	const giNote = outcome.gitignoreAppended
 		? " · .pygienium/ added to .gitignore"
@@ -341,6 +346,3 @@ export function registerPygieniumCommands(register: RegisterCommandFn): void {
 		handler: handleExportCommand,
 	});
 }
-
-/** Re-export for index.ts convenience. */
-export type { ExtensionUIContext };