fix: e2e.sh never sourced its own proofs, so none of them ran

Splitting e2e_proofs.sh out at the 250-line cap took the source line with
it. e2e.sh still called prove_the_add_photo_invariants, bash still reported
"command not found", and the script still exited 127 -- after every scenario
had already printed ok, which is why it read as a passing run with a stray
message at the end. CI has been red since 08599e6 for exactly this.

Six assertions were silently not running: that every stored file was
stripped, that a typed label never became a key in custom.json, that a
!dodaj carrying no attachment minted nothing, that refused uploads were not
stored, that signal-cli own copies were deleted, and that the adder was
recorded. All six pass now that they execute.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T4QTp3h5Q3MvfrwGV8xqPf

scripts/e2e.sh

@@ -13,6 +13,14 @@ set -euo pipefail
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 readonly SCRIPT_DIR
 REPO_ROOT="$(dirname "$SCRIPT_DIR")"
+
+# The post-replay assertions, split out at the 250-line cap. Sourced
+# rather than executed, because they run against the same fake server and
+# the same bot process the scenarios used -- and because the split lost
+# this line once already, which left every one of them silently unrun and
+# the whole script exiting 127.
+# shellcheck source=scripts/e2e_proofs.sh
+source "$SCRIPT_DIR/e2e_proofs.sh"
 readonly REPO_ROOT
 readonly PYTHON="${PYTHON:-$REPO_ROOT/.venv/bin/python}"
 readonly FAKE_PORT="${FAKE_PORT:-8099}"