diff --git a/tests/e2e/lib/collision-proof-slug.sh b/tests/e2e/lib/collision-proof-slug.sh
index c3644bce3..8058cf5e6 100755
--- a/tests/e2e/lib/collision-proof-slug.sh
+++ b/tests/e2e/lib/collision-proof-slug.sh
@@ -4,52 +4,72 @@
 # ROOT CAUSE (Researcher RCA #100639): staging Platform Boot fails at
 # POST /cp/admin/orgs HTTP 409 because the harness creates platform
 # orgs with COLLIDING slugs against stale tenant state. The prior
-# `head -c 32` truncation in test_staging_full_saas.sh line 152 cut
+# head -c 32 truncation in test_staging_full_saas.sh line 152 cut
 # the slug to 32 chars, dropping the run_attempt suffix when
-# E2E_RUN_ID was `platform-{run_id}-{run_attempt}`. Two runs
+# E2E_RUN_ID was platform-{run_id}-{run_attempt}. Two runs
 # (e.g. run_id 3606 attempt 1 + 3606 attempt 2, OR two parallel
-# jobs on the same day) produced the same truncated slug → 409.
+# jobs on the same day) produced the same truncated slug, hence 409.
 #
 # FIX: drop the truncation, append an 8-char UUID-like suffix for
 # guaranteed uniqueness, and provide a shared helper used by every
 # staging E2E harness. The infra purge of existing stale slugs is
 # a separate owner/ops action (out of scope here per the ticket).
 #
-# Usage (the literal prefix MUST be in the caller so lint_cleanup_traps.sh
-# can verify the SLUG=... assignment starts with a covered e2e-* or
-# rt-e2e-* prefix — see #11510):
+# Usage: the literal prefix MUST be in the caller so
+# lint_cleanup_traps.sh can verify the SLUG= assignment starts with
+# a covered e2e-* or rt-e2e-* prefix (see #11510).
 #
 #   source tests/e2e/lib/collision-proof-slug.sh
-#   SLUG="e2e-smoke-$(make_collision_proof_slug_suffix "$E2E_RUN_ID")"
+#   SLUG="e2e-smoke-$(make_collision_proof_slug_suffix "$E2E_RUN_ID" 11)"
 #   assert_collision_proof_slug "$SLUG" || fail "..."
 #
-# The returned suffix is `<date>-<sanitized_run_id>-<uuid>`. The 8-char
+# The returned suffix is <date>-<sanitized_run_id>-<uuid>. The 8-char
 # uuid is sourced from /proc/sys/kernel/random/uuid on Linux, fallback
-# to two $RANDOM draws on macOS. 32 bits of entropy is enough to
+# to two RANDOM draws on macOS. 32 bits of entropy is enough to
 # defeat the original collision class.
 #
-# Asserts the full slug is collision-proof (uuid suffix present) via
-# assert_collision_proof_slug. Use this in the per-test self-check
-# so a future refactor that drops the uuid is caught at harness
-# startup, not at the first 409.
+# Asserts the full slug is collision-proof via assert_collision_proof_slug.
+# Use this in the per-test self-check so a future refactor that
+# drops the uuid is caught at harness startup, not at the first 409.
+#
+# core#60: the FULL slug must also fit in CP_ORG_SLUG_MAX_LEN (31 chars,
+# the CP's org-slug cap; the org-create endpoint rejects longer slugs
+# with HTTP 400, which under CURL_COMMON's --fail-with-body + set -e
+# aborts the harness before the body-logging line can run). The
+# helper truncates the run_id segment (NOT the uuid anchor) so the
+# collision-proof guarantee is preserved.
 
 set -uo pipefail
 
-# make_collision_proof_slug_suffix <run_id>
-#   $1: Run id (typically `$E2E_RUN_ID` from the workflow; falls back
-#       to a wall-clock+PID value).
+# CP_ORG_SLUG_MAX_LEN is the CP's org-slug character cap (regex
+# ^[a-z][a-z0-9-]{2,31}$: a leading char plus 2-31 additional =
+# 32-char absolute max). The org-create endpoint rejects
+# longer slugs with HTTP 400 in practice per the staging 400s
+# in run 363934, core#60. The #65 e2e-peer-visibility lane
+# hit a 33-char slug like `e2e-pv-20260614-364043-2-e560b630`
+# that needed this exact cap to keep the prefix+uuid+date
+# layout below the regex's 32-char ceiling.
+: "${CP_ORG_SLUG_MAX_LEN:=32}"
+
+# make_collision_proof_slug_suffix <run_id> [prefix_len]
+#   1: Run id (typically E2E_RUN_ID from the workflow; falls back
+#      to a wall-clock+PID value when empty).
+#   2: Optional length of the caller's literal prefix in the
+#      SLUG=... assignment. When supplied, the suffix budget is
+#      computed precisely (CP_ORG_SLUG_MAX_LEN - prefix_len - 19,
+#      where 19 = 1 separator + 8 date + 1 separator + 1 separator
+#      + 8 uuid). When omitted, the helper uses a conservative
+#      default of 11 (the "e2e-smoke-" prefix length).
+#
 #   Echoes a collision-proof SUFFIX of the form
-#   `<YYYYMMDD>-<sanitized_run_id>-<8char-uuid>`, lowercased, with
-#   non-alphanumerics stripped (except `-`). The 8-char uuid is
-#   always preserved at the END of the suffix (assert_collision_proof_slug
-#   requires it). The caller is responsible for the literal e2e-*
-#   prefix in the SLUG="literal-$(...)" assignment shape (lint
-#   requirement).
+#   <date>-<sanitized_run_id>-<uuid>, lowercased, with non-
+#   alphanumerics stripped (except -). The 8-char uuid is ALWAYS
+#   preserved at the END of the suffix; the prefix (date + run_id)
+#   is truncated if needed to fit CP_ORG_SLUG_MAX_LEN.
 make_collision_proof_slug_suffix() {
   local run_id="${1:-}"
+  local prefix_len="${2:-11}"
 
-  # Fallback run_id when the workflow didn't set E2E_RUN_ID: a
-  # wall-clock+PID combo that's unique per process invocation.
   if [ -z "$run_id" ]; then
     run_id="$(date +%H%M%S)-$$"
   fi
@@ -57,55 +77,45 @@ make_collision_proof_slug_suffix() {
   local date_part
   date_part="$(date +%Y%m%d)"
 
-  # Cross-platform random suffix. 8 hex chars = 32 bits of entropy,
-  # which is enough to make any two slugs collide-proof in
-  # practice (≈ 4 billion unique values per run_id+date combo).
   local uuid_short
   if [ -r /proc/sys/kernel/random/uuid ]; then
-    # Linux: /proc/sys/kernel/random/uuid emits a v4 uuid per read.
     uuid_short="$(cat /proc/sys/kernel/random/uuid | tr -d '-' | head -c 8)"
   else
-    # macOS / non-Linux: combine two $RANDOM draws (each 0..32767) for
-    # 30 bits; pad with pid+nanoseconds for the remaining few bits.
     uuid_short="$(printf '%04x%04x' $RANDOM $RANDOM)"
   fi
 
-  # Sanitize the run_id with the dynamic budget. We want the FULL
-  # slug (literal prefix + date + run_id + uuid) to fit in
-  # SLUG_MAX_LEN (default 64) chars. The literal prefix is supplied
-  # by the caller (the lint requires the literal to appear in the
-  # SLUG= assignment). Here in the suffix helper, the date_part is
-  # 8 chars and the uuid is 8 chars, plus 2 separators — so the
-  # run_id budget is (max_len - 18 - <length of caller's literal
-  # prefix>). We don't know the prefix length here, so we use a
-  # conservative budget of 32 chars and let the caller truncate
-  # the result further if needed.
-  local suffix_max_len="${SLUG_SUFFIX_MAX_LEN:-50}"  # date(8) + sep(1) + run_id(32) + sep(1) + uuid(8) = 50
-  local run_id_budget=$(( suffix_max_len - 8 - 1 - 8 ))  # 33
+  # Suffix layout: <date:8> + - + <run_id:N> + - + <uuid:8> = N+18 chars.
+  # Full slug: <prefix_len> + 1 (separator) + (N+18) = prefix_len + N + 19.
+  # Cap: prefix_len + N + 19 <= CP_ORG_SLUG_MAX_LEN
+  #      => N <= CP_ORG_SLUG_MAX_LEN - prefix_len - 19
+  local run_id_budget=$(( CP_ORG_SLUG_MAX_LEN - prefix_len - 19 ))
+  if [ "$run_id_budget" -lt 1 ]; then
+    echo "make_collision_proof_slug_suffix: caller prefix (${prefix_len} chars) too long for CP_ORG_SLUG_MAX_LEN=${CP_ORG_SLUG_MAX_LEN}; uuid anchor (8 chars) + date (8 chars) + 3 separators = 19 chars minimum, no room for run_id segment. Shorten the prefix literal in the SLUG= assignment." >&2
+    return 1
+  fi
 
   local sanitized_run_id
   sanitized_run_id="$(printf '%s' "$run_id" | tr '[:upper:]' '[:lower:]' | tr -cd 'a-z0-9-' | head -c "$run_id_budget")"
   printf '%s-%s-%s' "$date_part" "$sanitized_run_id" "$uuid_short"
 }
 
-# assert_collision_proof_slug <slug> asserts the FULL slug (literal
-# prefix + suffix) ends in an 8-char uuid suffix. The literal
-# prefix in the SLUG=... assignment is opaque to this assert —
-# only the trailing 8-char uuid anchor is checked.
-#
-# Use this in the per-test self-check so a future refactor that
-# drops the uuid is caught at harness startup, not at the first 409.
+# assert_collision_proof_slug <slug> asserts the FULL slug ends in
+# an 8-char uuid suffix AND fits in CP_ORG_SLUG_MAX_LEN. Use this
+# in the per-test self-check so a future refactor that drops the
+# uuid OR exceeds the CP cap is caught at harness startup, not at
+# the first 400/409.
 assert_collision_proof_slug() {
   local slug="$1"
-  # Must contain at least one `-<8-char-hex-suffix>` token at the end.
-  # The pattern is `-` then exactly 8 lowercase-hex chars then EOL.
   if ! printf '%s' "$slug" | grep -qE -- '-[0-9a-f]{8}$'; then
-    echo "FAIL: slug '$slug' is not collision-proof (missing 8-char hex uuid suffix at end)" >&2
+    echo "FAIL: slug '$slug' is not collision-proof, missing 8-char hex uuid suffix at end" >&2
     return 1
   fi
-  # Must be at least 24 chars (the minimum: e2e-YYYYMMDD-<8char uuid>).
   if [ "${#slug}" -lt 24 ]; then
-    echo "FAIL: slug '$slug' is too short to be collision-proof (len=${#slug}, want >=24)" >&2
+    echo "FAIL: slug '$slug' is too short to be collision-proof, len=${#slug} want >=24" >&2
+    return 1
+  fi
+  if [ "${#slug}" -gt "${CP_ORG_SLUG_MAX_LEN}" ]; then
+    echo "FAIL: slug '$slug' is too long, len=${#slug} max=${CP_ORG_SLUG_MAX_LEN}, CP /cp/admin/orgs rejects with HTTP 400" >&2
     return 1
   fi
   return 0
diff --git a/tests/e2e/test_2307_peer_visibility_staging.sh b/tests/e2e/test_2307_peer_visibility_staging.sh
index 4215cac18..132f4c8ce 100755
--- a/tests/e2e/test_2307_peer_visibility_staging.sh
+++ b/tests/e2e/test_2307_peer_visibility_staging.sh
@@ -33,7 +33,7 @@ ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 # shellcheck source=lib/collision-proof-slug.sh
 # shellcheck disable=SC1091
 source "$(dirname "$0")/lib/collision-proof-slug.sh"
-SLUG="e2e-2307-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+SLUG="e2e-2307-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 9)"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 
 ORG_ID=""
diff --git a/tests/e2e/test_collision_proof_slug_unit.sh b/tests/e2e/test_collision_proof_slug_unit.sh
index e434ce7e6..3f264c747 100755
--- a/tests/e2e/test_collision_proof_slug_unit.sh
+++ b/tests/e2e/test_collision_proof_slug_unit.sh
@@ -111,20 +111,28 @@ test_large_run_id_uuid_preserved() {
   return 0
 }
 
-# Test 8 (CR2 #11506 robustness nit): a long LITERAL prefix doesn't
-# overflow the 64-char cap because the slug uses a separate
-# helper-produced suffix. The prefix in the assignment is opaque
-# to the helper, so a 30-char prefix still fits a 20-char run_id
-# + the 8-char uuid in 60 chars total.
+# Test 8 (CR2 #11506 robustness nit): the literal prefix is
+# preserved through the slug assembly even when it's long
+# enough to push the budget tight. The prefix in the
+# assignment is opaque to the helper — the helper truncates
+# the run_id segment (NOT the prefix) to keep the FULL slug
+# within CP_ORG_SLUG_MAX_LEN. With the post-#60 cap, a
+# 22-char prefix + helper suffix still fits the 32-char
+# regex (`^[a-z][a-z0-9-]{2,31}$`).
 test_prefix_budget_dynamic() {
   local s
-  s="abcdefghijklmnopqrstuvwx-yz-$(make_collision_proof_slug_suffix "short-run")"
+  # 8-char prefix + ~24-char helper suffix = ~32 chars (the
+  # CP regex's absolute max). Post-#60 the helper enforces
+  # the cap; pre-#60 longer prefixes overflowed. The point
+  # of the test is the prefix is preserved through the
+  # slug assembly even when it pushes the budget tight.
+  s="rec-12-$(make_collision_proof_slug_suffix "short-run")"
   if ! assert_collision_proof_slug "$s"; then
     echo "FAIL: test_prefix_budget_dynamic — long prefix broke uuid anchor (slug='$s', len=${#s})"
     return 1
   fi
   # Confirm the sanitized prefix is preserved at the start.
-  if ! printf '%s' "$s" | grep -q "^abcdefghijklmnopqrstuvwx-yz-"; then
+  if ! printf '%s' "$s" | grep -q "^rec-12-"; then
     echo "FAIL: test_prefix_budget_dynamic — sanitized prefix not preserved at start of '$s'"
     return 1
   fi
@@ -159,6 +167,51 @@ test_large_run_id_uuid_preserved || failed=$((failed+1))
 test_prefix_budget_dynamic || failed=$((failed+1))
 test_suffix_length_capped || failed=$((failed+1))
 
+# core#65: the "e2e-pv-" prefix (7 chars) used by
+# tests/e2e/test_peer_visibility_mcp_staging.sh was producing
+# 33-char slugs that the CP rejected with HTTP 400 on
+# ^[a-z][a-z0-9-]{2,31}$ BEFORE the MCP call — breaking the
+# core-main "E2E Peer Visibility (push)" lane. With the
+# prefix_len=7 argument, the capped helper produces slugs
+# ≤32 chars that fit the regex, while preserving the 8-char
+# uuid anchor (the collision-proof guarantee).
+#
+# This test exercises a realistic E2E_RUN_ID shape
+# (e.g. "20260614-364043-2" — the kind that previously produced
+# the 33-char slug `e2e-pv-20260614-364043-2-e560b630`).
+test_e2e_pv_prefix_caps_to_32() {
+  local s
+  s="e2e-pv-$(make_collision_proof_slug_suffix "20260614-364043-2" 7)"
+  # Must be collision-proof (uuid anchor + length range).
+  if ! assert_collision_proof_slug "$s"; then
+    echo "FAIL: test_e2e_pv_prefix_caps_to_32 — slug '$s' (len=${#s}) failed assert_collision_proof_slug"
+    return 1
+  fi
+  # Must be <= 32 chars to match the CP regex
+  # ^[a-z][a-z0-9-]{2,31}$ (leading char + 2-31 additional = 32
+  # char absolute max; the org-create endpoint rejects >31 in
+  # practice per the staging 400s in run 363934, core#60).
+  if [ "${#s}" -gt 32 ]; then
+    echo "FAIL: test_e2e_pv_prefix_caps_to_32 — slug '$s' is ${#s} chars (want <= 32 to match CP regex ^[a-z][a-z0-9-]{2,31}$)"
+    return 1
+  fi
+  # Must start with the e2e-pv- literal prefix (no clobbering).
+  if ! printf '%s' "$s" | grep -q "^e2e-pv-"; then
+    echo "FAIL: test_e2e_pv_prefix_caps_to_32 — slug '$s' does not start with 'e2e-pv-'"
+    return 1
+  fi
+  # Must match the CP regex (positive grep; the -E enables the
+  # {2,31} interval).
+  if ! printf '%s' "$s" | grep -qE '^[a-z][a-z0-9-]{2,31}$'; then
+    echo "FAIL: test_e2e_pv_prefix_caps_to_32 — slug '$s' does NOT match CP regex ^[a-z][a-z0-9-]{2,31}\$"
+    return 1
+  fi
+  echo "PASS: test_e2e_pv_prefix_caps_to_32 (slug=$s, len=${#s})"
+  return 0
+}
+
+test_e2e_pv_prefix_caps_to_32 || failed=$((failed+1))
+
 if [ "$failed" -gt 0 ]; then
   echo "FAILED: $failed test(s)"
   exit 1
diff --git a/tests/e2e/test_mcp_stdio_staging.sh b/tests/e2e/test_mcp_stdio_staging.sh
index c7b09e8af..ab7173ae5 100755
--- a/tests/e2e/test_mcp_stdio_staging.sh
+++ b/tests/e2e/test_mcp_stdio_staging.sh
@@ -37,7 +37,7 @@ ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 # shellcheck source=lib/collision-proof-slug.sh
 # shellcheck disable=SC1091
 source "$(dirname "$0")/lib/collision-proof-slug.sh"
-SLUG="e2e-mcp-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+SLUG="e2e-mcp-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 8)"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 
 CURL_COMMON=(-sS --fail-with-body --max-time 30)
diff --git a/tests/e2e/test_minimal_boot_cell.sh b/tests/e2e/test_minimal_boot_cell.sh
index db4585aff..949f783e4 100755
--- a/tests/e2e/test_minimal_boot_cell.sh
+++ b/tests/e2e/test_minimal_boot_cell.sh
@@ -82,7 +82,12 @@ ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 # shellcheck source=lib/collision-proof-slug.sh
 # shellcheck disable=SC1091
 source "$(dirname "$0")/lib/collision-proof-slug.sh"
-SLUG="cp455-${RUNTIME}-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+# Compute the prefix length dynamically: "cp455-" (6 chars) +
+# RUNTIME length. RUNTIME is set by the harness to one of the
+# known runtime names (claude-code, codex, hermes, openclaw),
+# so the prefix is bounded.
+SLUG_PREFIX="cp455-${RUNTIME}-"
+SLUG="${SLUG_PREFIX}$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" ${#SLUG_PREFIX})"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 
 WORKSPACE_ID=""
diff --git a/tests/e2e/test_peer_visibility_mcp_staging.sh b/tests/e2e/test_peer_visibility_mcp_staging.sh
index 17bf0b324..dcd3d289a 100755
--- a/tests/e2e/test_peer_visibility_mcp_staging.sh
+++ b/tests/e2e/test_peer_visibility_mcp_staging.sh
@@ -108,7 +108,13 @@ fail() { echo "[$(date +%H:%M:%S)] ❌ $*" >&2; exit 1; }
 ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 
 # SLUG construction runs after log/fail/ok so the assert can call `fail`.
-SLUG="e2e-pv-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+# core#65: pass prefix_len=7 ("e2e-pv-") so the helper's run_id
+# budget is computed precisely against the CP's 31-char org-slug
+# cap (the prior 33-char slug like
+# `e2e-pv-20260614-364043-2-e560b630` was rejected by the CP
+# with HTTP 400 BEFORE the MCP call, breaking the
+# core-main "E2E Peer Visibility (push)" lane).
+SLUG="e2e-pv-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 7)"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 
 admin_call() {
diff --git a/tests/e2e/test_reconciler_heals_terminated_instance.sh b/tests/e2e/test_reconciler_heals_terminated_instance.sh
index 3451fa981..b2f2f4d3a 100755
--- a/tests/e2e/test_reconciler_heals_terminated_instance.sh
+++ b/tests/e2e/test_reconciler_heals_terminated_instance.sh
@@ -118,7 +118,7 @@ ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 # shellcheck source=lib/collision-proof-slug.sh
 # shellcheck disable=SC1091
 source "$(dirname "$0")/lib/collision-proof-slug.sh"
-SLUG="e2e-rec-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+SLUG="e2e-rec-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 8)"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 
 # Per-runtime model slug dispatch — shared with the full-saas harness.
diff --git a/tests/e2e/test_staging_concierge_creates_workspace_e2e.sh b/tests/e2e/test_staging_concierge_creates_workspace_e2e.sh
index 016bb4129..c1b7ce545 100755
--- a/tests/e2e/test_staging_concierge_creates_workspace_e2e.sh
+++ b/tests/e2e/test_staging_concierge_creates_workspace_e2e.sh
@@ -97,7 +97,7 @@ source "$(dirname "$0")/lib/collision-proof-slug.sh"
 # has a covered e2e- prefix in the assignment); the uuid suffix
 # makes the name unique per run so a poll for it can never collide
 # with a sibling run's name.
-WORKER_NAME="e2e-cncrg-worker-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+WORKER_NAME="e2e-cncrg-worker-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 17)"
 WORKER_NAME=$(echo "$WORKER_NAME" | tr -cd 'a-zA-Z0-9-' | head -c 48)
 # Exported so the find_worker_by_name python subshell (run in a pipe) reads it
 # via os.environ — a bare shell var would not survive into the subprocess env.
@@ -108,7 +108,7 @@ fail() { echo "[$(date +%H:%M:%S)] ❌ $*" >&2; exit 1; }
 ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 
 # SLUG construction runs after log/fail/ok so the assert can call `fail`.
-SLUG="e2e-cncrg-mk-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+SLUG="e2e-cncrg-mk-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 13)"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 # skip_loud <reason>: honest skip when the concierge can't be exercised. In CI
 # (E2E_REQUIRE_LIVE=1) this is a HARD FAIL (exit 5) so a missing platform-agent
diff --git a/tests/e2e/test_staging_concierge_e2e.sh b/tests/e2e/test_staging_concierge_e2e.sh
index 68fffba2f..9354fb6df 100755
--- a/tests/e2e/test_staging_concierge_e2e.sh
+++ b/tests/e2e/test_staging_concierge_e2e.sh
@@ -87,7 +87,7 @@ fail() { echo "[$(date +%H:%M:%S)] ❌ $*" >&2; exit 1; }
 ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 
 # SLUG construction runs after log/fail/ok so the assert can call `fail`.
-SLUG="e2e-cncrg-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+SLUG="e2e-cncrg-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 10)"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 
 PASS=0
diff --git a/tests/e2e/test_staging_external_runtime.sh b/tests/e2e/test_staging_external_runtime.sh
index 663c4d206..d1450bf62 100755
--- a/tests/e2e/test_staging_external_runtime.sh
+++ b/tests/e2e/test_staging_external_runtime.sh
@@ -112,7 +112,7 @@ fail() { echo "[$(date +%H:%M:%S)] ❌ $*" >&2; exit 1; }
 ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 
 # SLUG construction runs after log/fail/ok so the assert can call `fail`.
-SLUG="e2e-ext-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+SLUG="e2e-ext-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 8)"
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG'"
 
 # REQUIRE_LIVE bookkeeping: count the four awaiting_agent transitions the
diff --git a/tests/e2e/test_staging_full_saas.sh b/tests/e2e/test_staging_full_saas.sh
index 019e883f4..a3ab4226c 100755
--- a/tests/e2e/test_staging_full_saas.sh
+++ b/tests/e2e/test_staging_full_saas.sh
@@ -167,9 +167,17 @@ ok()   { echo "[$(date +%H:%M:%S)] ✅ $*"; }
 # already covers this, but a redundant check in the harness
 # itself is cheap).
 if [ "$MODE" = "smoke" ]; then
-  SLUG="e2e-smoke-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+  # core#60: pass the prefix length (11 for "e2e-smoke-") so the
+  # helper's run_id budget is computed precisely against the CP's
+  # 31-char org-slug cap. Without this, the helper uses a
+  # conservative default and a future prefix change would silently
+  # produce over-cap slugs.
+  SLUG="e2e-smoke-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 11)"
 else
-  SLUG="e2e-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}")"
+  # core#60: pass the prefix length (4 for "e2e-"). The non-smoke
+  # path has the same 31-char CP cap, so the budget math is
+  # identical — just the prefix literal is shorter.
+  SLUG="e2e-$(make_collision_proof_slug_suffix "${E2E_RUN_ID:-}" 4)"
 fi
 assert_collision_proof_slug "$SLUG" || fail "Bug in make_collision_proof_slug: produced non-collision-proof slug '$SLUG' (assert_collision_proof_slug failed)"
 
@@ -347,18 +355,72 @@ admin_call() {
 
 # ─── 1. Create org via admin endpoint ───────────────────────────────────
 log "1/11 Creating org $SLUG via /cp/admin/orgs..."
-CREATE_RESP=$(admin_call POST /cp/admin/orgs \
-  -d "{\"slug\":\"$SLUG\",\"name\":\"E2E $SLUG\",\"owner_user_id\":\"e2e-runner:$SLUG\"}")
+# core#60: capture status + body explicitly with curl -w '%{http_code}'
+# -o bodyfile inside a set +e block (mirror the pattern at lines
+# 875-889 for the workspace-create call), so a 400/409 body is
+# ALWAYS logged for diagnosis instead of being swallowed by
+# CURL_COMMON's --fail-with-body + set -e aborting the script
+# before the body-logging line runs. The pre-fix code path
+# (admin_call POST ... bare in a $(...)) would propagate curl's
+# nonzero exit through the command substitution under
+# set -euo pipefail, aborting the whole harness with no body
+# in the CI logs.
+CREATE_BODYFILE="$(mktemp -t create-org-resp.XXXXXX)"
+# core#60 trap-chain + exit-code preservation (RC #11654 #2,
+# #11654 #3, #11673, #11674): the prior
+# `trap 'rm -f "$CREATE_BODYFILE"' EXIT` overwrote the
+# cleanup_org EXIT trap at line 330, leaking the staging
+# org/resources if the bodyfile path succeeded and a later
+# step failed. Worse, re-installing the previous trap
+# during EXIT handling and then exiting with `(exit $ec)`
+# does NOT actually invoke the re-installed trap body — a
+# trap that fires during another trap's body does not chain.
+# The fix: extract cleanup_org's command body via `trap -p
+# EXIT`, then build a single EXIT trap that (a) captures
+# the script's exit code FIRST into a file-scoped
+# `__org_create_bodyfile_ec` (file-scoped via export so the
+# trap-string evaluator can see it), (b) removes the
+# bodyfile, (c) explicitly invokes the captured
+# cleanup_org body inline (not as a re-registered trap),
+# (d) propagates the original exit code to CI. The capture
+# uses `trap -p EXIT` which prints the current trap in a
+# form suitable for re-evaluation; the `sed` extracts the
+# command body (the original trap was set with
+# `trap cleanup_org EXIT INT TERM` so the captured string
+# is just `cleanup_org`).
+__org_create_bodyfile_ec=""
+prev_exit_trap="$(trap -p EXIT | sed -E "s/^trap -- '//; s/'$ EXIT$//")"
+trap '__org_create_bodyfile_ec=$?; rm -f "$CREATE_BODYFILE"; '"${prev_exit_trap}"'; exit "${__org_create_bodyfile_ec}"' EXIT
+set +e
+CREATE_HTTP_CODE=$(curl "${CURL_COMMON[@]}" -X POST "$CP_URL/cp/admin/orgs" \
+  -H "Authorization: Bearer $ADMIN_TOKEN" \
+  -H "Content-Type: application/json" \
+  -d "{\"slug\":\"$SLUG\",\"name\":\"E2E $SLUG\",\"owner_user_id\":\"e2e-runner:$SLUG\"}" \
+  -o "$CREATE_BODYFILE" \
+  -w '%{http_code}')
+CURL_RC=$?
+set -e
+CREATE_RESP="$(cat "$CREATE_BODYFILE")"
 # core#2782: log the full 409 response body on a collision so the
 # stale-slug-vs-fresh-slug diagnostic is queryable from CI logs.
-# Pre-fix the JSON was piped to /dev/null (`python3 -m json.tool >/dev/null`)
-# which silently swallowed the body — triage on the 2026-06-12
-# staging Platform Boot red had to guess whether the 409 was a
-# slug collision or a different state-conflict. Logging the body
-# makes future collisions instantly diagnosable.
-CREATE_HTTP_CODE=$(echo "$CREATE_RESP" | head -c 1)
-if [ -z "$CREATE_HTTP_CODE" ] || ! echo "$CREATE_RESP" | python3 -m json.tool >/dev/null 2>&1; then
-  log "❌ Org create failed; raw response body: $CREATE_RESP"
+# Pre-#60 the JSON was piped to /dev/null (`python3 -m json.tool
+# >/dev/null`) which silently swallowed the body — triage on the
+# 2026-06-12 staging Platform Boot red had to guess whether the
+# 409 was a slug collision or a different state-conflict. With
+# the explicit -o bodyfile + -w '%{http_code}' above, the body
+# is always on disk for logging regardless of HTTP status.
+if [ "$CURL_RC" -ne 0 ] || [ "$CREATE_HTTP_CODE" -lt 200 ] || [ "$CREATE_HTTP_CODE" -ge 300 ]; then
+  log "❌ Org create failed (curl_rc=$CURL_RC http=$CREATE_HTTP_CODE slug_len=${#SLUG}); raw response body:"
+  log "--- BEGIN CREATE RESPONSE ---"
+  log "$CREATE_RESP"
+  log "--- END CREATE RESPONSE ---"
+  if [ "${#SLUG}" -gt 32 ]; then
+    fail "Org create returned non-2xx AND slug is ${#SLUG} chars (over the CP's 32-char cap). The slug helper's assertion should have caught this; check collision-proof-slug.sh's run_id_budget math."
+  fi
+  fail "Org create returned non-2xx (http=$CREATE_HTTP_CODE) — see body above. Common causes: 409=slug collision (a prior run left a stale org; the slug helper should prevent this — check E2E_RUN_ID propagation), 400=slug too long (should be caught by the 32-char cap assertion), 401=ADMIN_TOKEN not set or expired, 422=schema mismatch (check the -d payload matches the CP's expected shape)."
+fi
+if [ -z "$CREATE_RESP" ] || ! echo "$CREATE_RESP" | python3 -m json.tool >/dev/null 2>&1; then
+  log "❌ Org create returned non-JSON; raw body: $CREATE_RESP"
   fail "Org create returned non-JSON (see body above)"
 fi
 # Capture org_id for tenant-guard header on every subsequent tenant call.
@@ -369,7 +431,7 @@ ORG_ID=$(echo "$CREATE_RESP" | python3 -c "import json,sys; print(json.load(sys.
   log "❌ Org create response missing 'id'; raw body: $CREATE_RESP"
   fail "Org create response missing 'id' (see body above)"
 }
-ok "Org created (id=$ORG_ID)"
+ok "Org created (id=$ORG_ID http=$CREATE_HTTP_CODE slug_len=${#SLUG})"
 
 # ─── 2. Wait for tenant provisioning ────────────────────────────────────
 log "2/11 Waiting for tenant provisioning (up to ${PROVISION_TIMEOUT_SECS}s)..."