diff --git a/packages/cli/tests/refusal-redaction.test.mjs b/packages/cli/tests/refusal-redaction.test.mjs
index 4c1e9f87f..4f363c579 100644
--- a/packages/cli/tests/refusal-redaction.test.mjs
+++ b/packages/cli/tests/refusal-redaction.test.mjs
@@ -28,6 +28,22 @@ test('task file JSON refusal preserves exit 2 and file without parser bytes', t
   assert.match(r.stderr, /task file is not valid JSON/);
   assert.doesNotMatch(r.stdout + r.stderr, /sk-test|Unexpected token/);
 });
+test('task file read refusal retains exit 2, file and filesystem code', t => {
+  const file = write(join(scratch(t), 'task.json'), '{}');
+  // A directory is refused by lstat before the read. Inject a read failure
+  // after that unchanged regular-file gate, including on root-run CI hosts.
+  const preload = `import fs from 'node:fs';
+const read = fs.readFileSync;
+fs.readFileSync = function(path, ...args) {
+  if (path === ${JSON.stringify(file)}) throw Object.assign(new Error(${JSON.stringify(secret)}), { code: 'EIO' });
+  return read.call(this, path, ...args);
+};`;
+  const r = spawnSync(process.execPath, ['--import', 'data:text/javascript,' + encodeURIComponent(preload), join(repo, 'scripts/mosaic-task.mjs'), 'validate', file], { encoding: 'utf8', env: { PATH: process.env.PATH, HOME: process.env.HOME, TMPDIR: process.env.TMPDIR } });
+  assert.equal(r.status, 2, r.stderr);
+  assert.ok(r.stderr.includes(file), r.stderr);
+  assert.match(r.stderr, /task file is not valid JSON.*\(EIO\)/);
+  assert.doesNotMatch(r.stderr, /sk-test/);
+});
 test('case2 precheck business helper omits parser bytes in its BUSINESS fact', t => {
   const root = scratch(t), f = fixture(root);
   const file = write(join(root, 'config/businesses/acme.json'));
diff --git a/packages/control-board/src/scan.mjs b/packages/control-board/src/scan.mjs
index b50cf6390..9854812b2 100644
--- a/packages/control-board/src/scan.mjs
+++ b/packages/control-board/src/scan.mjs
@@ -37,8 +37,8 @@ export function loadConfig(path = defaultConfigPath()) {
   let raw;
   try {
     raw = parseJsonFileText(readFileSync(path, "utf8"), path);
-  } catch {
-    throw new ConfigError(`config is not valid JSON: ${path}`);
+  } catch (error) {
+    throw new ConfigError(`config is not valid JSON: ${path}${error.code ? ` (${error.code})` : ""}`);
   }
   if (!raw || typeof raw !== "object" || Array.isArray(raw)) throw new ConfigError(`config is not an object: ${path}`);
   if (typeof raw.dataRoot !== "string" || !isAbsolute(raw.dataRoot)) {
@@ -229,8 +229,8 @@ export function loadSeen(boardDir) {
   let parsed;
   try {
     parsed = parseJsonFileText(readFileSync(path, "utf8"), path);
-  } catch {
-    throw new ConfigError(`seen marks file is not valid JSON: ${path}`);
+  } catch (error) {
+    throw new ConfigError(`seen marks file is not valid JSON: ${path}${error.code ? ` (${error.code})` : ""}`);
   }
   if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) throw new ConfigError(`seen marks file must be a JSON object: ${path}`);
   for (const [k, v] of Object.entries(parsed)) {
diff --git a/packages/control-board/tests/refusal-redaction.test.mjs b/packages/control-board/tests/refusal-redaction.test.mjs
index e7f9b50e7..171af624b 100644
--- a/packages/control-board/tests/refusal-redaction.test.mjs
+++ b/packages/control-board/tests/refusal-redaction.test.mjs
@@ -32,3 +32,13 @@ for (const kind of ['config', 'seen']) test(`${kind} JSON refusal names only the
   const root = scratch(t), file = write(join(root, kind === 'config' ? 'config.json' : 'seen.json'));
   assert.throws(() => kind === 'config' ? loadConfig(file) : loadSeen(root), safe(file, ConfigError));
 });
+for (const kind of ['config', 'seen']) test(`${kind} read refusal retains the filesystem code`, t => {
+  const root = scratch(t), file = join(root, kind === 'config' ? 'config.json' : 'seen.json');
+  mkdirSync(file);
+  assert.throws(() => kind === 'config' ? loadConfig(file) : loadSeen(root), error => {
+    safe(file, ConfigError)(error);
+    assert.match(error.message, /\(EISDIR\)$/);
+    assert.doesNotMatch(error.message, /illegal operation/);
+    return true;
+  });
+});
diff --git a/packages/discord/src/binding.mjs b/packages/discord/src/binding.mjs
index c620997c8..fce460a15 100644
--- a/packages/discord/src/binding.mjs
+++ b/packages/discord/src/binding.mjs
@@ -61,8 +61,8 @@ export function loadDataRoot(path = defaultConfigPath()) {
   let raw;
   try {
     raw = parseJsonFileText(readFileSync(path, "utf8"), path);
-  } catch {
-    throw new DiscordError(`config is not valid JSON: ${path}`);
+  } catch (error) {
+    throw new DiscordError(`config is not valid JSON: ${path}${error.code ? ` (${error.code})` : ""}`);
   }
   if (!raw || typeof raw !== "object" || Array.isArray(raw)) throw new DiscordError(`config is not an object: ${path}`);
   if (typeof raw.dataRoot !== "string" || !isAbsolute(raw.dataRoot)) throw new DiscordError(`config.dataRoot must be an absolute path: ${path}`);
@@ -294,8 +294,8 @@ export function loadBinding(path) {
   let raw;
   try {
     raw = parseJsonFileText(readFileSync(path, "utf8"), path);
-  } catch {
-    throw new DiscordError(`binding is not valid JSON: ${path}`);
+  } catch (error) {
+    throw new DiscordError(`binding is not valid JSON: ${path}${error.code ? ` (${error.code})` : ""}`);
   }
   return validateBinding(raw, `binding ${path}`);
 }
diff --git a/packages/discord/tests/refusal-redaction.test.mjs b/packages/discord/tests/refusal-redaction.test.mjs
index 8638c0f59..12ad349be 100644
--- a/packages/discord/tests/refusal-redaction.test.mjs
+++ b/packages/discord/tests/refusal-redaction.test.mjs
@@ -49,3 +49,11 @@ test('tools environment JSON refusal names the config key without its bytes', ()
   try { assert.throws(() => extension({}), safe(TOOLS_ENV, Error)); }
   finally { if (previous === undefined) delete process.env[TOOLS_ENV]; else process.env[TOOLS_ENV] = previous; }
 });
+test('config read refusal retains the filesystem code', t => {
+  const file = scratch(t);
+  assert.throws(() => loadDataRoot(file), error => {
+    safe(file, DiscordError, { exitCode: 2 })(error);
+    assert.match(error.message, /\(EISDIR\)$/);
+    return true;
+  });
+});
diff --git a/packages/seat/src/seat.mjs b/packages/seat/src/seat.mjs
index 37d7c4650..6549daeaf 100644
--- a/packages/seat/src/seat.mjs
+++ b/packages/seat/src/seat.mjs
@@ -55,8 +55,8 @@ export function loadDataRoot(path = defaultConfigPath()) {
   let raw;
   try {
     raw = parseJsonFileText(readFileSync(path, "utf8"), path);
-  } catch {
-    throw new SeatError(`config is not valid JSON: ${path}`);
+  } catch (error) {
+    throw new SeatError(`config is not valid JSON: ${path}${error.code ? ` (${error.code})` : ""}`);
   }
   if (!raw || typeof raw !== "object" || Array.isArray(raw)) throw new SeatError(`config is not an object: ${path}`);
   if (typeof raw.dataRoot !== "string" || !isAbsolute(raw.dataRoot)) throw new SeatError(`config.dataRoot must be an absolute path: ${path}`);
@@ -204,8 +204,8 @@ export function readRegistration(seats, seat, layout) {
   let parsed;
   try {
     parsed = parseJsonFileText(readFileSync(path, "utf8"), path);
-  } catch {
-    throw new SeatError(`registration is not valid JSON: ${path}`);
+  } catch (error) {
+    throw new SeatError(`registration is not valid JSON: ${path}${error.code ? ` (${error.code})` : ""}`);
   }
   try {
     const record = validateRegistration(parsed);
diff --git a/packages/seat/tests/refusal-redaction.test.mjs b/packages/seat/tests/refusal-redaction.test.mjs
index 33b922648..74f9d96f7 100644
--- a/packages/seat/tests/refusal-redaction.test.mjs
+++ b/packages/seat/tests/refusal-redaction.test.mjs
@@ -32,3 +32,12 @@ for (const kind of ['config', 'registration']) test(`${kind} JSON refusal names
   const root = scratch(t), file = write(kind === 'config' ? join(root, 'config.json') : registrationPath(root, 'builder', 'repo'));
   assert.throws(() => kind === 'config' ? loadDataRoot(file) : readRegistration(root, 'builder', 'repo'), safe(file, SeatError, { exitCode: 2 }));
 });
+for (const kind of ['config', 'registration']) test(`${kind} read refusal retains the filesystem code`, t => {
+  const root = scratch(t), file = kind === 'config' ? join(root, 'config.json') : registrationPath(root, 'builder', 'repo');
+  mkdirSync(file, { recursive: true });
+  assert.throws(() => kind === 'config' ? loadDataRoot(file) : readRegistration(root, 'builder', 'repo'), error => {
+    safe(file, SeatError, { exitCode: 2 })(error);
+    assert.match(error.message, /\(EISDIR\)$/);
+    return true;
+  });
+});
diff --git a/scripts/mosaic-task.mjs b/scripts/mosaic-task.mjs
index d3659a200..4d251efe2 100755
--- a/scripts/mosaic-task.mjs
+++ b/scripts/mosaic-task.mjs
@@ -76,8 +76,8 @@ function readJsonFile(file, what) {
   let document;
   try {
     document = parseJsonFileText(fs.readFileSync(file, "utf8"), file, what);
-  } catch {
-    fail(2, `${what} is not valid JSON (${file})`);
+  } catch (error) {
+    fail(2, `${what} is not valid JSON (${file})${error.code ? ` (${error.code})` : ""}`);
   }
   return document;
 }
diff --git a/scripts/test-darkwing-launch.mjs b/scripts/test-darkwing-launch.mjs
index 883cdb1f0..c398c783b 100644
--- a/scripts/test-darkwing-launch.mjs
+++ b/scripts/test-darkwing-launch.mjs
@@ -32,6 +32,9 @@ for (const agent of ['darkwing', 'dewey', 'filbert', 'researcher', 'sage']) test
     // fixture is its own data root so no registration reaches a real one.
     cpSync(join(source, 'scripts/mosaic'), join(root, 'scripts/mosaic'));
     cpSync(join(source, 'packages/seat/src'), join(root, 'packages/seat/src'), { recursive: true });
+    mkdirSync(join(root, 'packages/organization/src'), { recursive: true });
+    for (const file of ['util.mjs', 'errors.mjs', 'vocabulary.mjs'])
+      cpSync(join(source, 'packages/organization/src', file), join(root, 'packages/organization/src', file));
     mkdirSync(join(root, '.git'));
     writeFileSync(join(root, 'config.json'), JSON.stringify({ configVersion: 1, dataRoot: root }));
     const registration = join(root, `seats/repo/${agent}/registration.json`);
@@ -149,40 +152,46 @@ test('default agent entry retains container setup and refuses missing seat/auth'
   try {
     for (const dir of ['scripts', 'bin', 'runtime/user']) mkdirSync(join(root, dir), { recursive: true });
     cpSync(join(source, 'scripts/agent.sh'), join(root, 'scripts/agent.sh'));
-    // All runtime effects remain in this fixture; Docker and release helpers are doubles.
+    // Observe the current processing-control handoff; its Docker behavior has
+    // its own package tests. Every runtime effect stays inside this fixture.
     writeFileSync(join(root, 'scripts/common.sh'), `
 load_config() { MOSAIC_DEV_DIR="$PWD/runtime"; MOSAIC_ADAPTER=pi; MOSAIC_MODEL=test; echo config >> trace; }
 load_release() { echo release >> trace; }
 bootstrap_runtime_dir() { echo bootstrap >> trace; }
+processing_guard() { echo processing >> trace; }
 ensure_release_aligned() { echo alignment >> trace; }
 `);
     writeFileSync(join(root, 'runtime/user/USER.md'), 'fixture user\n');
-    writeFileSync(join(root, 'bin/docker'), `#!/usr/bin/env node
-require('node:fs').writeFileSync('docker.json', JSON.stringify({
-args: process.argv.slice(2), session: process.env.MOSAIC_SESSION_DIR,
-workspace: process.env.MOSAIC_WORKSPACE, tools: process.env.MOSAIC_TOOLS,
-name: process.env.MOSAIC_AGENT_NAME, interactive: process.env.MOSAIC_INTERACTIVE
+    mkdirSync(join(root, 'packages/processing-control/src'), { recursive: true });
+    writeFileSync(join(root, 'packages/processing-control/src/container-cli.mjs'), `
+import fs from 'node:fs';
+fs.writeFileSync('container.json', JSON.stringify({
+args: process.argv.slice(2), session: process.env.MOSAIC_SESSION_DIR ?? null,
+workspace: process.env.MOSAIC_WORKSPACE ?? null, tools: process.env.MOSAIC_TOOLS,
+name: process.env.MOSAIC_AGENT_NAME, interactive: process.env.MOSAIC_INTERACTIVE,
+sessionSource: process.env.MOSAIC_SESSION_SOURCE, workspaceSource: process.env.MOSAIC_WORKSPACE_SOURCE
 }));
-`, { mode: 0o755 });
+`);
     const env = { ...process.env, PATH: join(root, 'bin') + ':' + process.env.PATH };
     for (const name of ['MOSAIC_AGENTS_DIR', 'MOSAIC_ROLES_DIR', 'MOSAIC_SKILLS', 'MOSAIC_AGENT_ROLE']) delete env[name];
     const run = (args, overrides = {}) => spawnSync('bash', [join(root, 'scripts/agent.sh'), ...args],
       { cwd: tmpdir(), env: { ...env, ...overrides }, encoding: 'utf8', timeout: 10000 });
     let result = run(['fixture', '--tools', 'read,bash']);
     assert.equal(result.status, 0, result.stdout + result.stderr);
-    assert.deepEqual(readFileSync(join(root, 'trace'), 'utf8').trim().split('\n'), ['config', 'release', 'bootstrap', 'alignment']);
-    assert.deepEqual(JSON.parse(readFileSync(join(root, 'docker.json'))), {
-      args: ['compose', 'run', '--rm', 'mosaic-agent'], session: '/var/lib/mosaic/sessions/agent-fixture',
-      workspace: '/var/lib/mosaic/workspaces/fixture', tools: 'read,bash', name: 'fixture', interactive: '1'
+    assert.deepEqual(readFileSync(join(root, 'trace'), 'utf8').trim().split('\n'), ['config', 'release', 'bootstrap', 'processing', 'alignment']);
+    assert.deepEqual(JSON.parse(readFileSync(join(root, 'container.json'))), {
+      args: ['--tty'], session: null,
+      workspace: null, tools: 'read,bash', name: 'fixture', interactive: '1',
+      sessionSource: join(root, 'runtime/sessions/agent-fixture'), workspaceSource: join(root, 'runtime/workspaces/fixture')
     });
-    const captured = readFileSync(join(root, 'docker.json'), 'utf8');
+    const captured = readFileSync(join(root, 'container.json'), 'utf8');
     result = run(['fixture'], { MOSAIC_AGENTS_DIR: join(root, 'missing-seats') });
     assert.equal(result.status, 4);
     assert.match(result.stderr, /no seat definition/);
     result = run(['fixture', '--auth', 'missing']);
     assert.equal(result.status, 4);
     assert.match(result.stderr, /no mosaic-managed credential/);
-    assert.equal(readFileSync(join(root, 'docker.json'), 'utf8'), captured);
+    assert.equal(readFileSync(join(root, 'container.json'), 'utf8'), captured);
     assert.equal(existsSync(join(root, '.pi')), false);
   } finally {
     rmSync(root, { recursive: true, force: true });
diff --git a/scripts/test-rocko-launch.mjs b/scripts/test-rocko-launch.mjs
index d591bcb0d..f84fa9710 100644
--- a/scripts/test-rocko-launch.mjs
+++ b/scripts/test-rocko-launch.mjs
@@ -23,6 +23,9 @@ test('Rocko uses Sonnet, isolated resume IDs, current context and launch refusal
     // Seat registration (packages/seat): the fixture is its own data root.
     cpSync(join(source, 'scripts/mosaic'), join(root, 'scripts/mosaic'));
     cpSync(join(source, 'packages/seat/src'), join(root, 'packages/seat/src'), { recursive: true });
+    mkdirSync(join(root, 'packages/organization/src'), { recursive: true });
+    for (const file of ['util.mjs', 'errors.mjs', 'vocabulary.mjs'])
+      cpSync(join(source, 'packages/organization/src', file), join(root, 'packages/organization/src', file));
     mkdirSync(join(root, '.git'));
     writeFileSync(join(root, 'config.json'), JSON.stringify({ configVersion: 1, dataRoot: root }));
     const registration = join(root, 'seats/repo/rocko/registration.json');