diff --git a/packages/electron/main.mjs b/packages/electron/main.mjs
index 98fcc87e..b706fcbc 100644
--- a/packages/electron/main.mjs
+++ b/packages/electron/main.mjs
@@ -285,6 +285,22 @@ const performConfirmedQuit = () => {
   app.exit(0);
 };
 
+// Hard-stop signals (`Ctrl+C` on `electron:dev`, an external `kill`/SIGTERM,
+// terminal close) bypass the normal app-quit flow — which would orphan the
+// in-process web server's managed OpenCode child. Run the same background
+// teardown the quit path uses (which kills the sidecar), then exit. The startup
+// reaper remains the backstop for an unhandled hard crash (SIGKILL).
+for (const signal of ['SIGINT', 'SIGTERM', 'SIGHUP']) {
+  process.on(signal, () => {
+    try {
+      shutdownBackgroundServices();
+    } catch (error) {
+      log.warn(`[electron] ${signal} shutdown failed:`, error);
+    }
+    app.exit(0);
+  });
+}
+
 const requestQuitWithConfirmation = async () => {
   await refreshQuitRiskFlags();
 
diff --git a/packages/vscode/src/opencode.ts b/packages/vscode/src/opencode.ts
index f1dd3631..efbaa374 100644
--- a/packages/vscode/src/opencode.ts
+++ b/packages/vscode/src/opencode.ts
@@ -9,6 +9,7 @@ import { spawn } from 'child_process';
 import { randomBytes } from 'crypto';
 import { normalizeWindowsDriveLetter } from './pathUtils';
 import { resolveWorkingDirectoryChange } from './workingDirectoryChange';
+import { registerManagedProcess, unregisterManagedProcess, reapOrphanedProcesses } from './opencodeProcessRegistry';
 
 const t = vscode.l10n.t;
 
@@ -688,6 +689,9 @@ async function spawnManagedOpenCodeServer(
     child.on('error', onError);
   });
 
+  // Record this child so a future run can reap it if we crash before teardown.
+  registerManagedProcess({ pid: child.pid, ownerPid: process.pid, port, binary, runtime: 'vscode' });
+
   return {
     url,
     close: () => {
@@ -696,6 +700,7 @@ async function spawnManagedOpenCodeServer(
       } catch {
         // ignore
       }
+      unregisterManagedProcess(child.pid);
     },
   };
 }
@@ -726,6 +731,7 @@ async function allocateManagedOpenCodePort(): Promise<number> {
 
 export function createOpenCodeManager(context: vscode.ExtensionContext): OpenCodeManager {
   let server: { url: string; close: () => void } | null = null;
+  let reapedOrphansOnce = false;
   let managedApiUrlOverride: string | null = null;
   let managedPassword: string | null = null;
   let managedPasswordSource: 'user-env' | 'generated' | 'rotated' | null = null;
@@ -866,6 +872,19 @@ export function createOpenCodeManager(context: vscode.ExtensionContext): OpenCod
       return;
     }
 
+    // Before spawning our own server, reap any OpenCode process WE spawned in a
+    // prior run that was orphaned by a crash/host-kill. Verified + scoped to our
+    // own pids, so it never touches a live instance's or the user's own server.
+    if (!reapedOrphansOnce) {
+      reapedOrphansOnce = true;
+      try {
+        const { reaped } = await reapOrphanedProcesses({ log: (msg) => console.log(msg) });
+        if (reaped > 0) console.log(`[opencode] startup reaped ${reaped} orphaned process(es)`);
+      } catch (error) {
+        console.warn('[opencode] orphan reap failed:', error instanceof Error ? error.message : error);
+      }
+    }
+
     setStatus('connecting');
     cliMissing = false;
     cliPath = null;
diff --git a/packages/vscode/src/opencodeProcessRegistry.ts b/packages/vscode/src/opencodeProcessRegistry.ts
new file mode 100644
index 00000000..903198c7
--- /dev/null
+++ b/packages/vscode/src/opencodeProcessRegistry.ts
@@ -0,0 +1,236 @@
+// Managed OpenCode process registry + orphan reaper — VS Code parity copy.
+//
+// The VS Code extension does NOT bundle the web package, so it cannot import
+// the web runtime's registry module. This is a parity implementation that
+// reads/writes the SAME on-disk registry directory and uses the SAME algorithm,
+// so a process spawned by any runtime (web, desktop, VS Code) can be reaped by
+// any other.
+//
+// Storage is ONE FILE PER SPAWNED PROCESS (`<childPid>.json`) in a registry
+// directory — never a single shared JSON file — because multiple runtimes and
+// windows run concurrently and a shared file would be clobbered by the
+// read-modify-write race. Per-process files mean each instance only ever writes
+// or deletes its OWN file.
+//
+// See packages/web/server/lib/opencode/managed-process-registry.js for the full
+// rationale and safety model. In short: we only ever kill pids THIS product
+// recorded, re-verified as a live `opencode serve`, and only when their spawner
+// is provably gone (reparented to pid 1, or recorded owner pid dead).
+
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { spawnSync } from 'node:child_process';
+
+type ManagedProcessEntry = {
+  pid: number;
+  ownerPid: number;
+  port: number | null;
+  binary: string | null;
+  runtime: string;
+  startedAt: string;
+};
+
+const resolveRegistryDir = (): string => {
+  const override = process.env.OPENCHAMBER_MANAGED_PROCESS_REGISTRY;
+  if (override && override.trim()) return override.trim();
+  return path.join(os.homedir(), '.config', 'openchamber', 'managed-opencode');
+};
+
+const entryFilePath = (pid: number): string => path.join(resolveRegistryDir(), `${pid}.json`);
+
+const writeEntryFile = (entry: ManagedProcessEntry): void => {
+  const dir = resolveRegistryDir();
+  try {
+    fs.mkdirSync(dir, { recursive: true });
+    const filePath = path.join(dir, `${entry.pid}.json`);
+    const tmp = `${filePath}.tmp-${process.pid}`;
+    fs.writeFileSync(tmp, JSON.stringify(entry, null, 2));
+    fs.renameSync(tmp, filePath);
+  } catch {
+    // Best-effort: a failed registry write must never break spawn/shutdown.
+  }
+};
+
+const readAllEntries = (): Array<{ entry: ManagedProcessEntry; filePath: string }> => {
+  const dir = resolveRegistryDir();
+  let names: string[] = [];
+  try {
+    names = fs.readdirSync(dir).filter((name) => name.endsWith('.json'));
+  } catch {
+    return [];
+  }
+  const out: Array<{ entry: ManagedProcessEntry; filePath: string }> = [];
+  for (const name of names) {
+    const filePath = path.join(dir, name);
+    try {
+      const entry = JSON.parse(fs.readFileSync(filePath, 'utf8'));
+      if (entry && Number.isInteger(entry.pid)) {
+        out.push({ entry: entry as ManagedProcessEntry, filePath });
+      } else {
+        fs.rmSync(filePath, { force: true });
+      }
+    } catch {
+      try { fs.rmSync(filePath, { force: true }); } catch { /* ignore */ }
+    }
+  }
+  return out;
+};
+
+export const registerManagedProcess = (input: {
+  pid: number | undefined;
+  ownerPid?: number;
+  port?: number | null;
+  binary?: string | null;
+  runtime?: string;
+}): void => {
+  const pid = input.pid;
+  if (!Number.isInteger(pid)) return;
+  writeEntryFile({
+    pid: pid as number,
+    ownerPid: Number.isInteger(input.ownerPid) ? (input.ownerPid as number) : process.pid,
+    port: Number.isInteger(input.port as number) ? (input.port as number) : null,
+    binary: typeof input.binary === 'string' ? input.binary : null,
+    runtime: typeof input.runtime === 'string' ? input.runtime : 'vscode',
+    startedAt: new Date().toISOString(),
+  });
+};
+
+export const unregisterManagedProcess = (pid: number | undefined): void => {
+  if (!Number.isInteger(pid)) return;
+  try {
+    fs.rmSync(entryFilePath(pid as number), { force: true });
+  } catch {
+    // ignore
+  }
+};
+
+const isPidAlive = (pid: number): boolean => {
+  if (!Number.isInteger(pid)) return false;
+  try {
+    process.kill(pid, 0);
+    return true;
+  } catch (error) {
+    return (error as NodeJS.ErrnoException)?.code === 'EPERM';
+  }
+};
+
+const sleep = (ms: number): Promise<void> => new Promise((resolve) => setTimeout(resolve, ms));
+
+const readUnixProcInfo = (pid: number): { ppid: number; command: string } | null => {
+  try {
+    const result = spawnSync('ps', ['-p', String(pid), '-o', 'ppid=,command='], {
+      encoding: 'utf8',
+      timeout: 3000,
+      windowsHide: true,
+    });
+    const line = (result.stdout || '').trim();
+    if (!line) return null;
+    const match = line.match(/^\s*(\d+)\s+(.*)$/);
+    if (!match) return null;
+    return { ppid: Number.parseInt(match[1], 10), command: match[2] };
+  } catch {
+    return null;
+  }
+};
+
+const readWindowsImageName = (pid: number): string | null => {
+  try {
+    const result = spawnSync('tasklist', ['/FI', `PID eq ${pid}`, '/FO', 'CSV', '/NH'], {
+      encoding: 'utf8',
+      timeout: 3000,
+      windowsHide: true,
+    });
+    return (result.stdout || '').trim() || null;
+  } catch {
+    return null;
+  }
+};
+
+const commandIdentifiesOurServer = (command: string, entry: ManagedProcessEntry): boolean => {
+  if (typeof command !== 'string') return false;
+  const lower = command.toLowerCase();
+  if (!lower.includes('opencode') || !lower.includes('serve')) return false;
+  if (Number.isInteger(entry.port) && !command.includes(String(entry.port))) return false;
+  return true;
+};
+
+const killOrphan = async (pid: number): Promise<void> => {
+  if (process.platform === 'win32') {
+    try {
+      spawnSync('taskkill', ['/PID', String(pid), '/T', '/F'], { stdio: 'ignore', timeout: 5000, windowsHide: true });
+    } catch {
+      // ignore
+    }
+    return;
+  }
+
+  const signalTree = (signal: NodeJS.Signals) => {
+    try { process.kill(-pid, signal); } catch { /* ignore */ }
+    try { process.kill(pid, signal); } catch { /* ignore */ }
+  };
+
+  signalTree('SIGTERM');
+  for (let waited = 0; waited < 1500 && isPidAlive(pid); waited += 150) {
+    await sleep(150);
+  }
+  if (isPidAlive(pid)) {
+    signalTree('SIGKILL');
+    await sleep(300);
+  }
+};
+
+const processEntry = async (
+  entry: ManagedProcessEntry,
+  log?: (message: string) => void,
+): Promise<boolean> => {
+  if (!isPidAlive(entry.pid)) return false;
+
+  const ownerGone = Number.isInteger(entry.ownerPid) && !isPidAlive(entry.ownerPid);
+
+  if (process.platform === 'win32') {
+    const image = readWindowsImageName(entry.pid);
+    const looksLikeOpencode = typeof image === 'string' && image.toLowerCase().includes('opencode');
+    if (looksLikeOpencode && ownerGone) {
+      await killOrphan(entry.pid);
+      log?.(`[opencode] reaped orphaned process pid ${entry.pid} (owner ${entry.ownerPid} gone)`);
+      return true;
+    }
+    return false;
+  }
+
+  const info = readUnixProcInfo(entry.pid);
+  if (!info || !commandIdentifiesOurServer(info.command, entry)) return false;
+
+  const orphaned = info.ppid === 1 || ownerGone;
+  if (!orphaned) return false;
+
+  await killOrphan(entry.pid);
+  log?.(`[opencode] reaped orphaned process pid ${entry.pid} (reparented/owner gone)`);
+  return true;
+};
+
+export const reapOrphanedProcesses = async (
+  options: { log?: (message: string) => void } = {},
+): Promise<{ inspected: number; reaped: number }> => {
+  const { log } = options;
+  const records = readAllEntries();
+  if (records.length === 0) return { inspected: 0, reaped: 0 };
+
+  let reaped = 0;
+  for (const { entry, filePath } of records) {
+    let drop = false;
+    try {
+      const wasReaped = await processEntry(entry, log);
+      if (wasReaped) reaped += 1;
+      drop = wasReaped || !isPidAlive(entry.pid);
+    } catch (error) {
+      log?.(`[opencode] reap check failed for pid ${entry.pid}: ${error instanceof Error ? error.message : error}`);
+    }
+    if (drop) {
+      try { fs.rmSync(filePath, { force: true }); } catch { /* ignore */ }
+    }
+  }
+
+  return { inspected: records.length, reaped };
+};
diff --git a/packages/web/server/lib/opencode/lifecycle.js b/packages/web/server/lib/opencode/lifecycle.js
index b03a8dae..ca1a82d5 100644
--- a/packages/web/server/lib/opencode/lifecycle.js
+++ b/packages/web/server/lib/opencode/lifecycle.js
@@ -1,5 +1,6 @@
 import { spawn, spawnSync } from 'node:child_process';
 import net from 'node:net';
+import { registerManagedProcess, unregisterManagedProcess, reapOrphanedProcesses } from './managed-process-registry.js';
 
 const parsePositiveInt = (value, fallback) => {
   const parsed = Number.parseInt(String(value ?? ''), 10);
@@ -140,7 +141,7 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
     });
   };
 
-  const closeManagedOpenCodeChild = async (child) => {
+  const terminateChildProcess = async (child) => {
     if (!child) {
       return;
     }
@@ -212,6 +213,19 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
     await waitForChildProcessClose(child, 1000);
   };
 
+  const closeManagedOpenCodeChild = async (child) => {
+    const pid = child?.pid;
+    try {
+      await terminateChildProcess(child);
+    } finally {
+      // Drop it from the registry only once it has actually exited, so a child
+      // that survived teardown stays eligible for the next run's reaper.
+      if (Number.isInteger(pid) && hasChildProcessExited(child)) {
+        unregisterManagedProcess(pid);
+      }
+    }
+  };
+
   const formatCapturedOutput = ({ stdout, stderr }) => {
     const parts = [];
     if (stdout.trim()) {
@@ -324,6 +338,19 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
       child.on('error', onError);
     });
 
+    // Record this child so a future run can reap it if we crash before teardown.
+    // The web-server lifecycle runs in-process inside multiple hosts, so tag the
+    // actual host (Electron sets OPENCHAMBER_RUNTIME='desktop'; the standalone
+    // web CLI leaves it unset → 'web'; SSH remote → 'ssh-remote') rather than a
+    // hardcoded label, matching the server's existing runtimeName convention.
+    registerManagedProcess({
+      pid: child.pid,
+      ownerPid: process.pid,
+      port,
+      binary,
+      runtime: process.env.OPENCHAMBER_RUNTIME || 'web',
+    });
+
     return {
       url,
       pid: child.pid || null,
@@ -747,6 +774,16 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
 
   const bootstrapOpenCodeAtStartup = async () => {
     try {
+      // Before doing anything, reap any OpenCode process WE spawned in a prior
+      // run that was orphaned by a crash/hard-exit. Verified + scoped to our own
+      // pids, so it never touches a live instance's or the user's own server.
+      try {
+        const { reaped } = await reapOrphanedProcesses({ log: (msg) => console.log(msg) });
+        if (reaped > 0) console.log(`[lifecycle] startup reaped ${reaped} orphaned OpenCode process(es)`);
+      } catch (error) {
+        console.warn('[lifecycle] orphan reap failed:', error?.message ?? error);
+      }
+
       syncFromHmrState();
       if (await isOpenCodeProcessHealthy()) {
         console.log(`[HMR] Reusing existing OpenCode process on port ${state.openCodePort}`);
diff --git a/packages/web/server/lib/opencode/managed-process-registry.js b/packages/web/server/lib/opencode/managed-process-registry.js
new file mode 100644
index 00000000..2e225bce
--- /dev/null
+++ b/packages/web/server/lib/opencode/managed-process-registry.js
@@ -0,0 +1,251 @@
+// Managed OpenCode process registry + orphan reaper.
+//
+// OpenChamber spawns the OpenCode server as an EXTERNAL child binary (on Unix
+// with `detached: true`, so it leads its own process group). That binary can
+// therefore outlive its parent if the parent is hard-killed/crashes/`Ctrl+C`ed
+// before graceful teardown runs — leaving an orphaned `opencode serve` that
+// then contends on the shared SQLite DB and slows everything down.
+//
+// We cannot tie an arbitrary external binary to the parent's death portably
+// (Electron's `utilityProcess` would, but it only runs JS entrypoints, not a
+// standalone binary). So we use the same pattern OpenCode's own CLI daemon uses
+// for its detached server: an on-disk record of the pids WE spawned, plus a
+// startup reaper that kills ONLY our own, verified, genuinely-orphaned
+// processes — never a process a live instance (another desktop window, a VS
+// Code host, the user's standalone `opencode`) is actively using.
+//
+// Storage: ONE FILE PER SPAWNED PROCESS in a registry directory, named
+// `<childPid>.json`. Multiple runtimes (web/desktop/VS Code) and multiple
+// windows all run concurrently; a single shared JSON file would be corrupted by
+// the read-modify-write race (last writer wins, clobbering another instance's
+// entry). Per-process files mean every instance only ever writes/deletes its
+// OWN file, so there is no write contention at all.
+//
+// Safety model (why this never kills the wrong thing):
+//   1. The reaper only ever considers pids THIS product recorded. The user's
+//      standalone CLI server, the official desktop app, and the TUI are never
+//      recorded, so they are never even candidates.
+//   2. Before killing, it re-verifies the live pid is still an `opencode serve`
+//      matching the recorded port (guards against the OS recycling a dead pid
+//      onto an unrelated process).
+//   3. It kills only when the spawning owner is provably gone — the child has
+//      been reparented to init/pid 1, or the recorded owner pid is dead. A
+//      child still owned by a live instance is left untouched.
+//
+// The VS Code extension cannot import this module (it does not bundle the web
+// package); it carries a parity implementation that reads/writes the SAME dir.
+
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { spawnSync } from 'node:child_process';
+
+const resolveRegistryDir = () => {
+  const override = process.env.OPENCHAMBER_MANAGED_PROCESS_REGISTRY;
+  if (override && override.trim()) return override.trim();
+  return path.join(os.homedir(), '.config', 'openchamber', 'managed-opencode');
+};
+
+const entryFilePath = (pid) => path.join(resolveRegistryDir(), `${pid}.json`);
+
+const writeEntryFile = (entry) => {
+  const dir = resolveRegistryDir();
+  try {
+    fs.mkdirSync(dir, { recursive: true });
+    const filePath = path.join(dir, `${entry.pid}.json`);
+    const tmp = `${filePath}.tmp-${process.pid}`;
+    fs.writeFileSync(tmp, JSON.stringify(entry, null, 2));
+    fs.renameSync(tmp, filePath);
+  } catch {
+    // Best-effort: a failed registry write must never break spawn/shutdown.
+  }
+};
+
+const readAllEntries = () => {
+  const dir = resolveRegistryDir();
+  let names = [];
+  try {
+    names = fs.readdirSync(dir).filter((name) => name.endsWith('.json'));
+  } catch {
+    return [];
+  }
+  const out = [];
+  for (const name of names) {
+    const filePath = path.join(dir, name);
+    try {
+      const entry = JSON.parse(fs.readFileSync(filePath, 'utf8'));
+      if (entry && Number.isInteger(entry.pid)) {
+        out.push({ entry, filePath });
+      } else {
+        fs.rmSync(filePath, { force: true });
+      }
+    } catch {
+      // Corrupt/partial file — drop it.
+      try { fs.rmSync(filePath, { force: true }); } catch {}
+    }
+  }
+  return out;
+};
+
+/** Record an OpenCode process WE spawned so a future run can reap it if orphaned. */
+export const registerManagedProcess = ({ pid, ownerPid, port, binary, runtime } = {}) => {
+  if (!Number.isInteger(pid)) return;
+  writeEntryFile({
+    pid,
+    ownerPid: Number.isInteger(ownerPid) ? ownerPid : process.pid,
+    port: Number.isInteger(port) ? port : null,
+    binary: typeof binary === 'string' ? binary : null,
+    runtime: typeof runtime === 'string' ? runtime : 'web',
+    startedAt: new Date().toISOString(),
+  });
+};
+
+/** Drop a pid from the registry (after we have killed/closed it ourselves). */
+export const unregisterManagedProcess = (pid) => {
+  if (!Number.isInteger(pid)) return;
+  try {
+    fs.rmSync(entryFilePath(pid), { force: true });
+  } catch {
+  }
+};
+
+const isPidAlive = (pid) => {
+  if (!Number.isInteger(pid)) return false;
+  try {
+    process.kill(pid, 0);
+    return true;
+  } catch (error) {
+    // EPERM = process exists but we lack permission to signal it → still alive.
+    return error?.code === 'EPERM';
+  }
+};
+
+const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
+
+// Returns { ppid, command } for a live pid on Unix, or null if it can't be read.
+const readUnixProcInfo = (pid) => {
+  try {
+    const result = spawnSync('ps', ['-p', String(pid), '-o', 'ppid=,command='], {
+      encoding: 'utf8',
+      timeout: 3000,
+      windowsHide: true,
+    });
+    const line = (result.stdout || '').trim();
+    if (!line) return null;
+    const match = line.match(/^\s*(\d+)\s+(.*)$/);
+    if (!match) return null;
+    return { ppid: Number.parseInt(match[1], 10), command: match[2] };
+  } catch {
+    return null;
+  }
+};
+
+// Windows image name for a pid (e.g. "opencode.exe"), or null.
+const readWindowsImageName = (pid) => {
+  try {
+    const result = spawnSync('tasklist', ['/FI', `PID eq ${pid}`, '/FO', 'CSV', '/NH'], {
+      encoding: 'utf8',
+      timeout: 3000,
+      windowsHide: true,
+    });
+    return (result.stdout || '').trim() || null;
+  } catch {
+    return null;
+  }
+};
+
+const commandIdentifiesOurServer = (command, entry) => {
+  if (typeof command !== 'string') return false;
+  const lower = command.toLowerCase();
+  if (!lower.includes('opencode') || !lower.includes('serve')) return false;
+  // Tie to the exact server we registered when we know its port, so a recycled
+  // pid running a *different* opencode server is never mistaken for ours.
+  if (Number.isInteger(entry.port) && !command.includes(String(entry.port))) return false;
+  return true;
+};
+
+const killOrphan = async (pid) => {
+  if (process.platform === 'win32') {
+    try {
+      spawnSync('taskkill', ['/PID', String(pid), '/T', '/F'], { stdio: 'ignore', timeout: 5000, windowsHide: true });
+    } catch {
+    }
+    return;
+  }
+
+  const signalTree = (signal) => {
+    try { process.kill(-pid, signal); } catch {}
+    try { process.kill(pid, signal); } catch {}
+  };
+
+  signalTree('SIGTERM');
+  for (let waited = 0; waited < 1500 && isPidAlive(pid); waited += 150) {
+    await sleep(150);
+  }
+  if (isPidAlive(pid)) {
+    signalTree('SIGKILL');
+    await sleep(300);
+  }
+};
+
+// Decide+act on a single registry entry. Returns true if it was reaped.
+const processEntry = async (entry, { log }) => {
+  // Dead pid → nothing to do (caller drops the file).
+  if (!isPidAlive(entry.pid)) return false;
+
+  const ownerGone = Number.isInteger(entry.ownerPid) && !isPidAlive(entry.ownerPid);
+
+  if (process.platform === 'win32') {
+    const image = readWindowsImageName(entry.pid);
+    const looksLikeOpencode = typeof image === 'string' && image.toLowerCase().includes('opencode');
+    // Windows lacks reliable reparent-to-1 semantics (job objects usually kill
+    // children with the parent), so we reap only when the owner is provably dead
+    // AND the image still looks like opencode.
+    if (looksLikeOpencode && ownerGone) {
+      await killOrphan(entry.pid);
+      log?.(`[lifecycle] reaped orphaned OpenCode pid ${entry.pid} (owner ${entry.ownerPid} gone)`);
+      return true;
+    }
+    return false;
+  }
+
+  const info = readUnixProcInfo(entry.pid);
+  // Can't verify identity (or it's not our server) → leave it alone.
+  if (!info || !commandIdentifiesOurServer(info.command, entry)) return false;
+
+  const orphaned = info.ppid === 1 || ownerGone;
+  if (!orphaned) return false; // still owned by a live instance
+
+  await killOrphan(entry.pid);
+  log?.(`[lifecycle] reaped orphaned OpenCode pid ${entry.pid} (reparented/owner gone)`);
+  return true;
+};
+
+/**
+ * Kill any genuinely-orphaned OpenCode processes WE previously spawned, and
+ * prune their registry files. Safe to call at startup before spawning a new
+ * server. Returns { inspected, reaped }.
+ */
+export const reapOrphanedProcesses = async ({ log } = {}) => {
+  const records = readAllEntries();
+  if (records.length === 0) return { inspected: 0, reaped: 0 };
+
+  let reaped = 0;
+  for (const { entry, filePath } of records) {
+    let drop = false;
+    try {
+      const wasReaped = await processEntry(entry, { log });
+      if (wasReaped) reaped += 1;
+      // Drop the file when the process is gone (reaped now, or already dead);
+      // keep it only while the process is still alive and owned by a live owner.
+      drop = wasReaped || !isPidAlive(entry.pid);
+    } catch (error) {
+      log?.(`[lifecycle] reap check failed for pid ${entry.pid}: ${error?.message ?? error}`);
+    }
+    if (drop) {
+      try { fs.rmSync(filePath, { force: true }); } catch {}
+    }
+  }
+
+  return { inspected: records.length, reaped };
+};
diff --git a/packages/web/server/lib/opencode/server-startup-runtime.js b/packages/web/server/lib/opencode/server-startup-runtime.js
index 551badd5..e53a14ae 100644
--- a/packages/web/server/lib/opencode/server-startup-runtime.js
+++ b/packages/web/server/lib/opencode/server-startup-runtime.js
@@ -131,9 +131,15 @@ export const createServerStartupRuntime = (dependencies) => {
       const handleSignal = async () => {
         await gracefulShutdown();
       };
+      // Cover every signal a shell or dev harness may use to stop/restart us, so
+      // the managed OpenCode child is always torn down gracefully instead of
+      // orphaned: SIGINT/SIGQUIT (Ctrl+C/Ctrl+\), SIGTERM (kill/default), SIGHUP
+      // (terminal close), SIGUSR2 (nodemon restart for `dev:server:watch`).
       process.on('SIGTERM', handleSignal);
       process.on('SIGINT', handleSignal);
       process.on('SIGQUIT', handleSignal);
+      process.on('SIGHUP', handleSignal);
+      process.on('SIGUSR2', handleSignal);
       setSignalsAttached(true);
       syncToHmrState();
     }