refactor: wave 2 - split atlas, auto-update-checker, session-recovery, todo-enforcer, background-task hooks

- Extract atlas/ into 15 focused modules (hook, event handler, tool policies, types, etc.)
- Split auto-update-checker into checker/ and hook/ subdirectories with single-purpose files
- Decompose session-recovery into separate recovery strategy files per error type
- Extract todo-continuation-enforcer from monolith to directory with dedicated modules
- Split background-task/tools.ts into individual tool creator files
- Extract command-executor, tmux-utils into focused sub-modules
- Split config/schema.ts into domain-specific schema files
- Decompose cli/config-manager.ts into focused modules
- Rollback skill-mcp-manager, model-availability, index.ts splits that broke tests
- Fix all import path depths for moved files (../../ -> ../../../)
- Add explicit type annotations to resolve TS7006 implicit any errors

Typecheck: 0 errors
Tests: 2359 pass, 5 fail (all pre-existing)

src/shared/tmux/tmux-utils/pane-replace.ts

@@ -0,0 +1,69 @@
+import { spawn } from "bun"
+import type { TmuxConfig } from "../../../config/schema"
+import { getTmuxPath } from "../../../tools/interactive-bash/tmux-path-resolver"
+import type { SpawnPaneResult } from "../types"
+import { isInsideTmux } from "./environment"
+
+export async function replaceTmuxPane(
+	paneId: string,
+	sessionId: string,
+	description: string,
+	config: TmuxConfig,
+	serverUrl: string,
+): Promise<SpawnPaneResult> {
+	const { log } = await import("../../logger")
+
+	log("[replaceTmuxPane] called", { paneId, sessionId, description })
+
+	if (!config.enabled) {
+		return { success: false }
+	}
+	if (!isInsideTmux()) {
+		return { success: false }
+	}
+
+	const tmux = await getTmuxPath()
+	if (!tmux) {
+		return { success: false }
+	}
+
+	log("[replaceTmuxPane] sending Ctrl+C for graceful shutdown", { paneId })
+	const ctrlCProc = spawn([tmux, "send-keys", "-t", paneId, "C-c"], {
+		stdout: "pipe",
+		stderr: "pipe",
+	})
+	await ctrlCProc.exited
+
+	const opencodeCmd = `opencode attach ${serverUrl} --session ${sessionId}`
+
+	const proc = spawn([tmux, "respawn-pane", "-k", "-t", paneId, opencodeCmd], {
+		stdout: "pipe",
+		stderr: "pipe",
+	})
+	const exitCode = await proc.exited
+
+	if (exitCode !== 0) {
+		const stderr = await new Response(proc.stderr).text()
+		log("[replaceTmuxPane] FAILED", { paneId, exitCode, stderr: stderr.trim() })
+		return { success: false }
+	}
+
+	const title = `omo-subagent-${description.slice(0, 20)}`
+	const titleProc = spawn([tmux, "select-pane", "-t", paneId, "-T", title], {
+		stdout: "ignore",
+		stderr: "pipe",
+	})
+	const stderrPromise = new Response(titleProc.stderr).text().catch(() => "")
+	const titleExitCode = await titleProc.exited
+	if (titleExitCode !== 0) {
+		const titleStderr = await stderrPromise
+		log("[replaceTmuxPane] WARNING: failed to set pane title", {
+			paneId,
+			exitCode: titleExitCode,
+			stderr: titleStderr.trim(),
+		})
+	}
+
+	log("[replaceTmuxPane] SUCCESS", { paneId, sessionId })
+	return { success: true, paneId }
+}