diff --git a/BUILD-LOG.md b/BUILD-LOG.md
index 0fc6aeac..0bc3a757 100644
--- a/BUILD-LOG.md
+++ b/BUILD-LOG.md
@@ -553,3 +553,31 @@ Auth is checkpointable without exposing credentials, and multi-account has
 a per-launch path. Suites 24/90/14/17/13 + verify green. The agreed
 ROADMAP sequence M16–M19 is complete; M20 (packages/* restructure +
 unified CLI) is owner-gated.
+
+## Phase 24 follow-up: auth ownership corrected — data root, never ~/.pi (#48)
+
+- Owner correction after M19 review: mosaic-managed named accounts must
+  not live inside ~/.pi — the stack must never impact default harness
+  usage. Recorded as a ROADMAP standing decision: the stack never writes
+  to default harness config locations; ~/.pi is read-only to the stack.
+- Correction noted honestly: M19 as shipped placed accounts beside
+  ~/.pi/agent/auth.json. Nothing had been created there (accounts reported
+  none), so the move breaks nothing.
+- auth.sh is now config-driven (data root from config.json, fail closed —
+  consistent with every other tool); status reports both sources labeled:
+  default harness credential (read-only to the stack) + mosaic-managed
+  accounts.
+- Accounts live at <dataRoot>/auth/<account>.json, perms 0600 enforced:
+  loose perms flagged in listings and refused by agent.sh --auth
+  (mirrors scripts/gitea-api.sh credential hygiene).
+- Test-authoring correction: the first suite rewrite asserted "(none)" in
+  cases whose fixtures had already created accounts; caught on review
+  before any run, assertions rewritten to match fixture state.
+- auth.sh suite: 13 → 15 cases (accounts-create-nothing, loose-perms
+  refusal, invalid-config refusal added).
+
+## Result
+
+Suites 24/15/90/14/17 + verify green. Default harness usage is untouched
+by design; all mosaic-managed credentials live inside the governed data
+root.
diff --git a/README.md b/README.md
index 60aef767..9c299fff 100644
--- a/README.md
+++ b/README.md
@@ -210,6 +210,8 @@ Pi's documented container authentication (see the package's
    passes them through. Pi's documented precedence applies.
 
 Credentials are never committed, never copied into the image, and never printed.
+Mosaic-managed named accounts (`agent.sh --auth`) live under the data root
+(`auth/<account>.json`, 0600) — the stack never writes into `~/.pi`.
 `.env.example` contains non-secret settings only.
 
 ## Boundaries honored
diff --git a/docs/SESSIONS.md b/docs/SESSIONS.md
index b4005d10..c0833af0 100644
--- a/docs/SESSIONS.md
+++ b/docs/SESSIONS.md
@@ -14,3 +14,4 @@ are never rewritten or removed; corrections are new entries.
 | 2026-09-03 | assistant (conductor) | M18 seat-role progressive capability restriction (#45): roles/<role>.json contracts (strict schema, name-filename binding, network declared), mosaic-task.mjs resolve-role, agent.sh ceiling intersection with fail-closed refusals, roles/researcher.json shipped, 14 suite cases (task 74 → 88) | scripts/mosaic-task.mjs, scripts/agent.sh, scripts/test-task.sh, roles/researcher.json, docs; suites 24/88/14/17 + verify green |
 | 2026-09-03 | owner (decision + live verification) + assistant (conductor) | M18 live verification + follow-up (#46): owner confirmed narrowing/refusal/tool-free live; seatless launch under AGENTS_DIR override discovered and made fail-closed (exit 4); task suite 88 → 90 | scripts/agent.sh, scripts/test-task.sh, docs/TOOLS.md; suites 24/90/14/17 + verify green |
 | 2026-09-03 | assistant (conductor) | M19 harness auth tooling (#47): pi auth investigation (native provider stacking, no native multi-account), scripts/auth.sh status/accounts (never prints credential material), agent.sh --auth per-launch injection via PI_AUTH_FILE, test-auth.sh suite (13 cases incl. secret-never-printed assertions) | scripts/auth.sh, scripts/agent.sh, scripts/test-auth.sh, docs/TOOLS.md, AGENTS.md; suites 24/90/14/17/13 + verify green |
+| 2026-09-03 | owner (direction) + assistant (conductor) | M19 correction (#48): mosaic-managed auth moved from ~/.pi to the data root (auth/<account>.json, 0600 enforced); ~/.pi read-only to the stack as a ROADMAP standing decision; auth.sh config-driven; test-auth 15 cases | scripts/auth.sh, scripts/agent.sh, scripts/test-auth.sh, docs/TOOLS.md, docs/plans/ROADMAP.md, README.md; suites 24/15/90/14/17 + verify green |
diff --git a/docs/TOOLS.md b/docs/TOOLS.md
index 94c0a577..3c88ed1d 100644
--- a/docs/TOOLS.md
+++ b/docs/TOOLS.md
@@ -65,14 +65,21 @@ provider; resolution order `--api-key` → `auth.json` → env → models.json).
 No credential material is ever printed — provider names, credential types,
 and env var NAMES only.
 
+Ownership rule (#48): `~/.pi` is read-only to the stack, permanently. The
+only interaction is the existing read-only container mount of the default
+credential (`PI_AUTH_FILE`, default `~/.pi/agent/auth.json`). Mosaic-managed
+accounts live under the data root: `<dataRoot>/auth/<account>.json`, perms
+0600 (mirroring `scripts/gitea-api.sh` hygiene — loose perms are flagged in
+listings and refused by `--auth`).
+
 | Command | Purpose | Notes |
 |---|---|---|
-| `scripts/auth.sh status` | Per-provider credential report | Types (`oauth`/`api_key`), perms, env-side names (informational); exit 3 when the file is missing |
-| `scripts/auth.sh accounts` | List named account files | `auth.<account>.json` beside the credential file; marks the active one |
+| `scripts/auth.sh status` | Report both credential sources | Default harness credential (read-only) + mosaic-managed accounts; never prints material |
+| `scripts/auth.sh accounts` | List mosaic-managed accounts | Under the data root; marks the active one; flags non-0600 |
 
-The file is the compose read-only mount source (`PI_AUTH_FILE`, default
-`~/.pi/agent/auth.json`); named accounts ride the same mount per launch via
-`agent.sh --auth`. Headless task runs keep the default credential.
+`agent.sh --auth <account>` injects `<dataRoot>/auth/<account>.json` as the
+launch's `PI_AUTH_FILE`; missing/symlinked/non-0600 accounts refuse.
+Headless task runs keep the default credential.
 
 ## Release
 
diff --git a/docs/plans/CURRENT.md b/docs/plans/CURRENT.md
index 3d878c32..5575712b 100644
--- a/docs/plans/CURRENT.md
+++ b/docs/plans/CURRENT.md
@@ -53,3 +53,4 @@ git history + Gitea issues.
 - 2026-09-03 — M18 seat-role progressive capability restriction (#45; roles resolve to contracts, ceiling ∩ seat grant, fail-closed refusals, roles/researcher.json); task suite 74 → 88
 - 2026-09-03 — M18 follow-up: fail-closed seat resolution under MOSAIC_AGENTS_DIR override (#46, owner decision after live verification); task suite 88 → 90; next action M19
 - 2026-09-03 — M19 harness auth tooling (#47; auth.sh status/accounts, agent.sh --auth per-launch injection via PI_AUTH_FILE, test-auth suite 13 cases with secret-never-printed assertions); agreed sequence M16–M19 complete, M20 owner-gated
+- 2026-09-03 — M19 correction: auth ownership moved to the data root (#48, owner direction — the stack never writes to default harness config locations; ROADMAP standing decision); auth.sh config-driven, accounts at <dataRoot>/auth, 0600 enforced; test-auth 13 → 15
diff --git a/docs/plans/ROADMAP.md b/docs/plans/ROADMAP.md
index 26df67ca..3d866ce8 100644
--- a/docs/plans/ROADMAP.md
+++ b/docs/plans/ROADMAP.md
@@ -17,6 +17,10 @@ and BUILD-LOG phase.
   referenced from AGENTS.md.
 - **Capability restriction becomes progressive and role-based** (M18),
   porting prior Mosaic Stack concepts where they fit the file-based runtime.
+- **The stack never writes to default harness config locations** (owner,
+  2026-09-03, #48): `~/.pi` — and any future harness home — is read-only to
+  Mosaic tooling; the only interaction is the existing read-only credential
+  mount. Mosaic-managed auth lives under the data root (`<dataRoot>/auth/`).
 
 ## M16 — Release self-determination
 
diff --git a/scripts/agent.sh b/scripts/agent.sh
index a1d1f95b..c7269fe6 100755
--- a/scripts/agent.sh
+++ b/scripts/agent.sh
@@ -41,25 +41,28 @@ done
 [ -n "$NAME" ] || { echo "agent: usage: scripts/agent.sh <name> [--mission f] [--workspace ws] [--session s] [--tools list] [--auth account]" >&2; exit 4; }
 case "$NAME" in *[!A-Za-z0-9._-]*|'') echo "agent: invalid agent name" >&2; exit 4;; esac
 
-# Named auth account (M19): per-launch credential injection. Resolves
-# auth.<account>.json beside the active credential file and exports
-# PI_AUTH_FILE (the compose read-only mount source). A missing or invalid
-# account refuses - silently falling back to the default credential would
-# put one account's work on another's identity.
-if [ -n "$AUTH_ACCOUNT" ]; then
-    case "$AUTH_ACCOUNT" in *[!A-Za-z0-9._-]*|'') echo "agent: invalid auth account name" >&2; exit 4;; esac
-    AUTH_DIR="$(dirname "${PI_AUTH_FILE:-$HOME/.pi/agent/auth.json}")"
-    AUTH_RESOLVED="$AUTH_DIR/auth.$AUTH_ACCOUNT.json"
-    [ -r "$AUTH_RESOLVED" ] && [ ! -L "$AUTH_RESOLVED" ] || { echo "agent: no credential file for auth account '$AUTH_ACCOUNT': $AUTH_RESOLVED" >&2; exit 4; }
-    export PI_AUTH_FILE="$AUTH_RESOLVED"
-    echo "agent: auth: account '$AUTH_ACCOUNT' -> $AUTH_RESOLVED" >&2
-fi
-
 load_config
 load_release
 bootstrap_runtime_dir
 ensure_release_aligned
 
+# Named auth account (M19, corrected per owner in #48): per-launch
+# credential injection from MOSAIC-MANAGED storage under the data root —
+# never from inside ~/.pi, which is read-only to the stack. Resolves
+# <dataRoot>/auth/<account>.json and exports PI_AUTH_FILE (the compose
+# read-only mount source). Missing, symlinked, or non-0600 files refuse:
+# silently falling back to another credential would put one account's work
+# on another's identity.
+if [ -n "$AUTH_ACCOUNT" ]; then
+    case "$AUTH_ACCOUNT" in *[!A-Za-z0-9._-]*|'') echo "agent: invalid auth account name" >&2; exit 4;; esac
+    AUTH_RESOLVED="$MOSAIC_DEV_DIR/auth/$AUTH_ACCOUNT.json"
+    [ -r "$AUTH_RESOLVED" ] && [ ! -L "$AUTH_RESOLVED" ] || { echo "agent: no mosaic-managed credential file for auth account '$AUTH_ACCOUNT': $AUTH_RESOLVED (see scripts/auth.sh accounts)" >&2; exit 4; }
+    AUTH_PERMS="$(stat -c %a "$AUTH_RESOLVED")"
+    [ "$AUTH_PERMS" = "600" ] || { echo "agent: auth account '$AUTH_ACCOUNT' file must be 0600 (got $AUTH_PERMS): $AUTH_RESOLVED" >&2; exit 4; }
+    export PI_AUTH_FILE="$AUTH_RESOLVED"
+    echo "agent: auth: account '$AUTH_ACCOUNT' -> $AUTH_RESOLVED" >&2
+fi
+
 # Onboarding gate (M16): a TUI agent cannot launch without a user profile.
 # The onboarding wizard runs automatically here - the TTY is already yours.
 if [ ! -f "$MOSAIC_DEV_DIR/user/USER.md" ]; then
diff --git a/scripts/auth.sh b/scripts/auth.sh
index 50adb4ce..dd414e7e 100755
--- a/scripts/auth.sh
+++ b/scripts/auth.sh
@@ -1,36 +1,42 @@
 #!/usr/bin/env bash
-# auth.sh — pi credential checkpoint (M19): per-provider auth report and
-# named-account listing. Never prints credential material: provider names,
-# credential types, permission bits, and env var NAMES only.
+# auth.sh — pi credential checkpoint (M19, corrected per owner in #48):
+# per-provider auth report and mosaic-managed account listing. Never prints
+# credential material: provider names, credential types, permission bits,
+# and env var NAMES only.
+#
+# Ownership rule (#48): ~/.pi is READ-ONLY to the stack — the only
+# interaction is the existing read-only container mount of the default
+# credential. Mosaic-managed accounts live under the data root:
+#   <dataRoot>/auth/<account>.json
 #
 # Usage:
-#   scripts/auth.sh status     per-provider report (auth.json + env-side names)
-#   scripts/auth.sh accounts   list named account files (auth.<account>.json)
-#
-# The credential file is the compose read-only mount source (PI_AUTH_FILE,
-# default ~/.pi/agent/auth.json). Resolution follows pi: auth.json entries
-# take priority over environment variables.
+#   scripts/auth.sh status     report default harness credential + accounts
+#   scripts/auth.sh accounts   list mosaic-managed accounts (data root)
 #
 # Exit codes: 0 report produced · 2 credential file unparseable ·
-# 3 file/dir missing for a read · 4 file/environment problem.
+# 3 default credential file missing for a read · 4 file/environment problem.
 set -uo pipefail
 cd "$(dirname "$0")/.."
+# shellcheck source=common.sh
+source scripts/common.sh
+load_config   # fail closed: data root comes from the system config
 
-AUTH_FILE="${PI_AUTH_FILE:-$HOME/.pi/agent/auth.json}"
-AUTH_DIR="$(dirname "$AUTH_FILE")"
+HARNESS_FILE="${PI_AUTH_FILE:-$HOME/.pi/agent/auth.json}"
+ACCOUNTS_DIR="$MOSAIC_DEV_DIR/auth"
 OP="${1:-}"
 
-case "$OP" in
-    status)
-        if [ ! -e "$AUTH_FILE" ]; then
-            echo "auth: credential file not found: $AUTH_FILE" >&2
-            exit 3
-        fi
-        if [ ! -f "$AUTH_FILE" ] || [ -L "$AUTH_FILE" ]; then
-            echo "auth: credential file must be a regular, non-symbolic-link file: $AUTH_FILE" >&2
-            exit 4
-        fi
-        if ! node -e '
+# report_file FILE — providers + types for a pi auth.json; never values.
+report_file() {
+    local file="$1"
+    if [ ! -e "$file" ]; then
+        echo "    (not present)"
+        return 3
+    fi
+    if [ ! -f "$file" ] || [ -L "$file" ]; then
+        echo "auth: credential file must be a regular, non-symbolic-link file: $file" >&2
+        return 4
+    fi
+    if ! node -e '
 const fs = require("fs");
 const file = process.argv[1];
 let doc;
@@ -40,45 +46,69 @@ if (typeof doc !== "object" || doc === null || Array.isArray(doc)) {
   console.error("auth: credential file must be a JSON object keyed by provider"); process.exit(2);
 }
 const st = fs.statSync(file);
-console.log("auth file: " + file + " (perms " + String(st.mode & 0o777).toString(8).padStart(3, "0") + ")");
+console.log("    perms " + String(st.mode & 0o777).toString(8).padStart(3, "0"));
 const keys = Object.keys(doc).sort();
-if (keys.length === 0) console.log("providers: (none in file)");
+if (keys.length === 0) console.log("    providers: (none in file)");
 for (const k of keys) {
   const e = doc[k];
   let type = "unknown";
   if (typeof e === "object" && e !== null && typeof e.type === "string" && /^[a-z0-9_-]+$/i.test(e.type)) type = e.type;
-  console.log("  " + k + "  type=" + type + "  source=auth.json");
+  console.log("    " + k + "  type=" + type + "  source=auth.json");
 }
-console.log("resolution: auth.json entries take priority over environment (pi order: --api-key > auth.json > env > models.json)");
-' "$AUTH_FILE"; then
-            exit 2
-        fi
+' "$file"; then
+        return 2
+    fi
+    return 0
+}
+
+case "$OP" in
+    status)
+        echo "default harness credential (read-only to the stack; never written): $HARNESS_FILE"
+        RC=0
+        report_file "$HARNESS_FILE" || RC=$?
+        echo "resolution: auth.json entries take priority over environment (pi order: --api-key > auth.json > env > models.json)"
         ENV_NAMES="$(env | grep -oE '^[A-Z0-9_]+_API_KEY' | sort -u | paste -sd, -)"
         if [ -n "$ENV_NAMES" ]; then
             echo "env-side credential-like names set (informational; file entries take priority): $ENV_NAMES"
         else
             echo "env-side credential-like names set: (none)"
         fi
-        ;;
-    accounts)
-        if [ ! -d "$AUTH_DIR" ]; then
-            echo "auth: directory not found: $AUTH_DIR" >&2
-            exit 3
-        fi
+        echo "mosaic-managed accounts ($ACCOUNTS_DIR):"
         shopt -s nullglob
-        FILES=("$AUTH_DIR"/auth.*.json)
+        FILES=("$ACCOUNTS_DIR"/*.json)
         shopt -u nullglob
         if [ "${#FILES[@]}" -eq 0 ]; then
-            echo "accounts: (none) — named accounts are auth.<account>.json beside the credential file"
+            echo "    (none)"
+        else
+            for f in "${FILES[@]}"; do
+                name="$(basename "$f" .json)"
+                perms="$(stat -c %a "$f" 2>/dev/null || echo '?')"
+                marker=""
+                [ "$f" = "$HARNESS_FILE" ] && marker="  <- active (PI_AUTH_FILE)"
+                warn=""
+                [ "$perms" != "600" ] && warn="  [not 0600 — agent --auth will refuse]"
+                echo "    $name  (perms $perms)$marker$warn"
+            done
+        fi
+        exit "$RC"
+        ;;
+    accounts)
+        shopt -s nullglob
+        FILES=("$ACCOUNTS_DIR"/*.json)
+        shopt -u nullglob
+        if [ "${#FILES[@]}" -eq 0 ]; then
+            echo "accounts: (none) — mosaic-managed accounts are $ACCOUNTS_DIR/<account>.json (perms 0600)"
             exit 0
         fi
-        echo "named accounts in $AUTH_DIR:"
+        echo "mosaic-managed accounts in $ACCOUNTS_DIR:"
         for f in "${FILES[@]}"; do
             name="$(basename "$f" .json)"
-            name="${name#auth.}"
+            perms="$(stat -c %a "$f" 2>/dev/null || echo '?')"
             marker=""
-            [ "$f" = "$AUTH_FILE" ] && marker="  <- active (PI_AUTH_FILE)"
-            echo "  $name$marker"
+            [ "$f" = "$HARNESS_FILE" ] && marker="  <- active (PI_AUTH_FILE)"
+            warn=""
+            [ "$perms" != "600" ] && warn="  [not 0600 — agent --auth will refuse]"
+            echo "  $name  (perms $perms)$marker$warn"
         done
         ;;
     *)
diff --git a/scripts/test-auth.sh b/scripts/test-auth.sh
index d556be25..de032483 100755
--- a/scripts/test-auth.sh
+++ b/scripts/test-auth.sh
@@ -1,10 +1,11 @@
 #!/usr/bin/env bash
-# Fast, sandboxed selftests for the auth checkpoint (M19).
+# Fast, sandboxed selftests for the auth checkpoint (M19, corrected in #48).
 #
-# No Docker, no network, no real credentials: every case runs against
-# fixture files via PI_AUTH_FILE. The suite asserts the core safety
-# property: credential MATERIAL from fixtures never reaches auth.sh or
-# agent.sh output.
+# No Docker, no network, no real credentials. Mosaic-managed accounts live
+# under the data root (config-driven, like every other tool); the default
+# harness credential appears only as an explicit PI_AUTH_FILE fixture.
+# The suite asserts the core safety property: credential MATERIAL from
+# fixtures never reaches auth.sh or agent.sh output.
 set -uo pipefail
 cd "$(dirname "$0")/.."
 
@@ -27,22 +28,36 @@ check() {
 SECRET="SK-TEST-DO-NOT-PRINT-9f2b"
 TOKEN="ACCESS-TOKEN-SHOULD-NOT-PRINT"
 ENVVAL="ENVVAL-SHOULD-NOT-PRINT"
-mkdir -p "$SANDBOX/creds" "$SANDBOX/empty"
-printf '{"anthropic":{"type":"oauth","access":"%s"},"zai":{"type":"api_key","key":"%s"}}' "$TOKEN" "$SECRET" > "$SANDBOX/creds/auth.json"
-printf '{}' > "$SANDBOX/creds/auth.work.json"
-printf '{}' > "$SANDBOX/creds/auth.personal.json"
+mkdir -p "$SANDBOX/pi" "$SANDBOX/data/auth" "$SANDBOX/data/state" "$SANDBOX/empty"
 
-# status: missing credential file -> exit 3 (config missing for a read)
-OUT="$(PI_AUTH_FILE="$SANDBOX/creds/absent.json" scripts/auth.sh status 2>"$SANDBOX/err.txt")"; RC=$?
-[ "$RC" -eq 3 ] && grep -q "credential file not found" "$SANDBOX/err.txt" \
-    && check "status on missing credential file exits 3" 0 || check "status on missing credential file exits 3" 1
+# mock system config: data root inside the sandbox (never the real one)
+printf '{"configVersion":1,"environment":"development","dataRoot":"%s","execution":{"backend":"docker","provider":"zai","model":"m","adapter":"mock"}}' "$SANDBOX/data" > "$SANDBOX/mock-config.json"
+CFG="MOSAIC_CONFIG=$SANDBOX/mock-config.json"
 
-# status: happy path — providers sorted with credential types
-OUT="$(PI_AUTH_FILE="$SANDBOX/creds/auth.json" scripts/auth.sh status 2>&1)"; RC=$?
+# release pointer so agent.sh's ensure stays on the no-op fast path
+REL="$(tr -d '[:space:]' < RELEASE)"
+printf '{"pointerVersion":1,"release":"%s","imageTag":"mosaic-poc-agent:0.84.4-r%s","activatedAt":"2026-01-01T00:00:00Z"}\n' "$REL" "$REL" > "$SANDBOX/data/state/active.json"
+
+# fixtures: a default-harness credential and two mosaic-managed accounts
+printf '{"anthropic":{"type":"oauth","access":"%s"},"zai":{"type":"api_key","key":"%s"}}' "$TOKEN" "$SECRET" > "$SANDBOX/pi/auth.json"
+printf '{}' > "$SANDBOX/data/auth/work.json"
+printf '{}' > "$SANDBOX/data/auth/personal.json"
+chmod 600 "$SANDBOX/pi/auth.json" "$SANDBOX/data/auth/work.json" "$SANDBOX/data/auth/personal.json"
+
+# status: missing default harness credential -> exit 3, accounts still listed
+OUT="$(env PI_AUTH_FILE="$SANDBOX/pi/absent.json" $CFG scripts/auth.sh status 2>"$SANDBOX/err.txt")"; RC=$?
+[ "$RC" -eq 3 ] \
+    && printf '%s\n' "$OUT" | grep -q '  work  (perms 600)' \
+    && check "status with missing harness credential exits 3 and still lists accounts" 0 || check "status with missing harness credential exits 3 and still lists accounts" 1
+
+# status: happy path — harness providers + mosaic accounts, both labeled
+OUT="$(env PI_AUTH_FILE="$SANDBOX/pi/auth.json" $CFG scripts/auth.sh status 2>&1)"; RC=$?
 [ "$RC" -eq 0 ] \
+    && printf '%s\n' "$OUT" | grep -q 'read-only to the stack' \
     && printf '%s\n' "$OUT" | grep -q '  anthropic  type=oauth  source=auth\.json' \
     && printf '%s\n' "$OUT" | grep -q '  zai  type=api_key  source=auth\.json' \
-    && check "status lists providers with credential types" 0 || check "status lists providers with credential types" 1
+    && printf '%s\n' "$OUT" | grep -q 'mosaic-managed accounts' \
+    && check "status reports harness credential (read-only) + mosaic accounts" 0 || check "status reports harness credential (read-only) + mosaic accounts" 1
 
 # the core safety property: fixture secret material never reaches output
 printf '%s\n' "$OUT" | grep -q "$SECRET" \
@@ -50,48 +65,61 @@ printf '%s\n' "$OUT" | grep -q "$SECRET" \
 printf '%s\n' "$OUT" | grep -q "$TOKEN" \
     && check "oauth token material never reaches output" 1 || check "oauth token material never reaches output" 0
 
-# status: unparseable file -> exit 2
-printf 'not json' > "$SANDBOX/creds/broken.json"
-PI_AUTH_FILE="$SANDBOX/creds/broken.json" scripts/auth.sh status >/dev/null 2>&1; RC=$?
+# status: unparseable harness file -> exit 2
+printf 'not json' > "$SANDBOX/pi/broken.json"
+env PI_AUTH_FILE="$SANDBOX/pi/broken.json" $CFG scripts/auth.sh status >/dev/null 2>&1; RC=$?
 [ "$RC" -eq 2 ] && check "unparseable credential file exits 2" 0 || check "unparseable credential file exits 2" 1
 
-# status: symlinked credential file -> exit 4 (must be a regular file)
-ln -s "$SANDBOX/creds/auth.json" "$SANDBOX/creds/link.json"
-PI_AUTH_FILE="$SANDBOX/creds/link.json" scripts/auth.sh status >/dev/null 2>&1; RC=$?
+# status: symlinked harness file -> exit 4
+ln -s "$SANDBOX/pi/auth.json" "$SANDBOX/pi/link.json"
+env PI_AUTH_FILE="$SANDBOX/pi/link.json" $CFG scripts/auth.sh status >/dev/null 2>&1; RC=$?
 [ "$RC" -eq 4 ] && check "symlinked credential file exits 4" 0 || check "symlinked credential file exits 4" 1
 
-# status: env-side names are informational — name shown, value never
-OUT="$(FAKE_TEST_API_KEY=$ENVVAL PI_AUTH_FILE="$SANDBOX/creds/auth.json" scripts/auth.sh status 2>&1)"
+# status: env-side names informational — name shown, value never
+OUT="$(env FAKE_TEST_API_KEY=$ENVVAL PI_AUTH_FILE="$SANDBOX/pi/auth.json" $CFG scripts/auth.sh status 2>&1)"
 printf '%s\n' "$OUT" | grep -q "FAKE_TEST_API_KEY" \
     && check "env-side credential names reported" 0 || check "env-side credential names reported" 1
 printf '%s\n' "$OUT" | grep -q "$ENVVAL" \
     && check "env var values never reach output" 1 || check "env var values never reach output" 0
 
-# accounts: empty directory -> (none), exit 0
-OUT="$(PI_AUTH_FILE="$SANDBOX/empty/auth.json" scripts/auth.sh accounts 2>&1)"; RC=$?
-[ "$RC" -eq 0 ] && printf '%s\n' "$OUT" | grep -q "(none)" \
-    && check "accounts with no named files reports none" 0 || check "accounts with no named files reports none" 1
+# accounts: mosaic-managed, under the data root — a data root with no accounts dir is the default state: (none), exit 0, creates nothing
+printf '{"configVersion":1,"environment":"development","dataRoot":"%s","execution":{"backend":"docker","provider":"zai","model":"m","adapter":"mock"}}' "$SANDBOX/empty" > "$SANDBOX/mock-config-empty.json"
+OUT="$(env PI_AUTH_FILE="$SANDBOX/pi/auth.json" MOSAIC_CONFIG="$SANDBOX/mock-config-empty.json" scripts/auth.sh accounts 2>&1)"; RC=$?
+[ "$RC" -eq 0 ] && printf '%s\n' "$OUT" | grep -q '(none)' && [ ! -d "$SANDBOX/empty/auth" ] \
+    && check "accounts without an accounts dir reports none and creates nothing" 0 || check "accounts without an accounts dir reports none and creates nothing" 1
 
 # accounts: listing with active marker
-OUT="$(PI_AUTH_FILE="$SANDBOX/creds/auth.work.json" scripts/auth.sh accounts 2>&1)"; RC=$?
-[ "$RC" -eq 0 ] && printf '%s\n' "$OUT" | grep -q '^  work  <- active (PI_AUTH_FILE)$' \
-    && printf '%s\n' "$OUT" | grep -q '^  personal$' \
+OUT="$(env PI_AUTH_FILE="$SANDBOX/data/auth/work.json" $CFG scripts/auth.sh accounts 2>&1)"; RC=$?
+printf '%s\n' "$OUT" | grep -q '^  work  (perms 600)  <- active (PI_AUTH_FILE)$' \
+    && printf '%s\n' "$OUT" | grep -q '^  personal  (perms 600)$' \
     && check "accounts lists files and marks the active one" 0 || check "accounts lists files and marks the active one" 1
 
-# accounts: missing directory -> exit 3
-PI_AUTH_FILE="$SANDBOX/nodir/auth.json" scripts/auth.sh accounts >/dev/null 2>&1; RC=$?
-[ "$RC" -eq 3 ] && check "accounts on missing directory exits 3" 0 || check "accounts on missing directory exits 3" 1
+# accounts: loose perms flagged loudly
+printf '{}' > "$SANDBOX/data/auth/loose.json"
+chmod 644 "$SANDBOX/data/auth/loose.json"
+OUT="$(env $CFG scripts/auth.sh accounts 2>&1)"
+printf '%s\n' "$OUT" | grep -q 'loose  (perms 644)  \[not 0600 — agent --auth will refuse\]' \
+    && check "loose account perms flagged in listing" 0 || check "loose account perms flagged in listing" 1
 
-# agent.sh --auth: missing account file refuses before any container work
-scripts/agent.sh researcher --auth nope </dev/null >/dev/null 2>"$SANDBOX/err.txt"; RC=$?
-[ "$RC" -eq 4 ] && grep -q "no credential file for auth account 'nope'" "$SANDBOX/err.txt" \
+# agent.sh --auth: missing mosaic-managed account file refuses (pre-container)
+env $CFG scripts/agent.sh researcher --auth nope </dev/null >/dev/null 2>"$SANDBOX/err.txt"; RC=$?
+[ "$RC" -eq 4 ] && grep -q "no mosaic-managed credential file for auth account 'nope'" "$SANDBOX/err.txt" \
     && check "agent --auth with missing account file refuses (exit 4)" 0 || check "agent --auth with missing account file refuses (exit 4)" 1
 
+# agent.sh --auth: loose perms refuse (0600 required, mirroring gitea-api.sh)
+env $CFG scripts/agent.sh researcher --auth loose </dev/null >/dev/null 2>"$SANDBOX/err.txt"; RC=$?
+[ "$RC" -eq 4 ] && grep -q "must be 0600 (got 644)" "$SANDBOX/err.txt" \
+    && check "agent --auth with non-0600 account file refuses" 0 || check "agent --auth with non-0600 account file refuses" 1
+
 # agent.sh --auth: invalid account name refuses
-scripts/agent.sh researcher --auth "bad~name" </dev/null >/dev/null 2>"$SANDBOX/err.txt"; RC=$?
+env $CFG scripts/agent.sh researcher --auth "bad~name" </dev/null >/dev/null 2>"$SANDBOX/err.txt"; RC=$?
 [ "$RC" -eq 4 ] && grep -q "invalid auth account name" "$SANDBOX/err.txt" \
     && check "agent --auth with invalid account name refuses" 0 || check "agent --auth with invalid account name refuses" 1
 
+# auth.sh: invalid config refuses (fail closed, like every tool)
+MOSAIC_CONFIG="$SANDBOX/no-such-config.json" scripts/auth.sh status >/dev/null 2>&1; RC=$?
+[ "$RC" -ne 0 ] && check "auth.sh without valid config refuses" 0 || check "auth.sh without valid config refuses" 1
+
 echo
 echo "selftest: $PASS passed, $FAIL failed"
 [ "$FAIL" -eq 0 ]