build the secret store: one key per purpose, none in .env

.env now holds PORT and POSTGRES_URL. Every encryption and signing key lives in
$OFFICER_ROOT/secrets/officer-keys.db — 0600, 0700 directory, owned by the
service user, created on first use.

The design doc planned to move ONE at-rest key into the store. What shipped
splits it: headscale, wallet, photos, jellyfin, invoiceshelf, vault and
service-connections each get their own, plus jwt. VAULT_STORE_KEY encrypted all
seven, so one leak opened all of them — and it was named after whichever plugin
needed it first, which is why it read as safe to change if you did not run a
vault. A core install bootstraps two, jwt and headscale; the rest appear when
their plugin first asks.

The file IS the secret. No second key unlocks it, because a key beside the store
it opens buys nothing. The gain was never secrecy, it is blast radius: bun
auto-loads .env into all twenty pm2 processes, so a key there is readable from
/proc/<pid>/environ of twenty processes — officer-music held the key that
decrypts wallet seed envelopes.

Two defects found by testing the store rather than reading it, both of which
would have shipped:

  The WAL was 0644. Enabling WAL creates -wal and -shm at 0644 rather than
  inheriting the database's mode, and a freshly written key lives in the WAL
  before checkpoint — so the 0600 on the database was decorative. The 0700
  directory covered it, but only until someone loosened the directory.

  PRAGMA journal_mode = WAL takes an exclusive lock, and busy_timeout was set
  AFTER it. With twelve concurrent openers, six died on that line with
  SQLITE_BUSY. Every sidecar opens this store at boot, so they open it
  simultaneously by definition: most of them would have failed to start on a cold
  boot and none on a warm one. Fixed by ordering the pragmas; re-tested with
  twelve racing processes, one key, one row.

crypto.ts takes a purpose as its first argument now, which the design doc had
explicitly promised would not happen — 32 call sites across seven query modules.
That promise is corrected in the doc rather than quietly dropped.

Also live, not just comments: wallet/upstream.ts gated wallet storage on
process.env.VAULT_STORE_KEY and would have reported "unconfigured" forever. It
asks the store now, and the question it answers changed — not "did somebody set a
variable" but "can this process open the store", since the key is created on
demand.

assertSecretsClosed covers the store, its directory and its WAL. The jwt key
mints owner tokens, so a member's shell reading it is strictly worse than the
.env leak that check was written for.

Not typechecked: node_modules is empty and installs are frozen, so the
officerdb/secret-store subpath could not be resolved at runtime here — verified
that officerdb/types fails identically, so it is the empty tree and not the new
export. The store module itself was tested directly: creation, idempotence across
processes, hasKey not creating, permissions, and the twelve-way race. Every
changed file parses; the setup section runs and degrades correctly when the
import is unavailable.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/servers/os-user.ts

@@ -1,6 +1,7 @@
 import { chmod, mkdir, readdir, stat } from 'node:fs/promises';
 import { existsSync } from 'node:fs';
-import { join } from 'node:path';
+import { dirname, join } from 'node:path';
+import { secretStorePath } from 'officerdb/secret-store';
 import { DATA_PATH, USER_DIRS, toShellUsername } from './data-path';
 
 // Real Linux accounts for members, so the surfaces that execute code can run as them.
@@ -464,6 +465,9 @@ export async function confineUserTree(params: {
  * gets skipped. Returns the offending paths; the caller decides whether that is fatal.
  */
 export async function findReadableSecrets(projectDir: string): Promise<string[]> {
+  // The store is not in projectDir — it sits at $OFFICER_ROOT/secrets/, a sibling of the repo — so it is
+  // checked separately below. Its keys are strictly worse to leak than .env ever was: the 'jwt' purpose
+  // mints owner tokens, and every other purpose decrypts a credential column in Postgres.
   const candidates = ['.env', '.env.local', '.env.production'];
   const bad: string[] = [];
   for (const name of candidates) {
@@ -477,6 +481,21 @@ export async function findReadableSecrets(projectDir: string): Promise<string[]>
       // Unreadable to us is not a leak to them; nothing to report.
     }
   }
+
+  // The secret store and its directory. The WAL is included deliberately: a freshly written key lives
+  // there before checkpoint, so a 0600 database beside a world-readable WAL protects nothing.
+  const storeFile = secretStorePath();
+  const storeDir = dirname(storeFile);
+  for (const path of [storeDir, storeFile, `${storeFile}-wal`, `${storeFile}-shm`]) {
+    if (!existsSync(path)) continue;
+    try {
+      const info = await stat(path);
+      if (info.mode & 0o044) bad.push(path);
+    } catch {
+      // Same reasoning as above.
+    }
+  }
+
   return bad;
 }