Make the copyable recipe independent of ambient set -e behavior. A failed tmux new-session now reports the failure and exits while session_owned is still false; only a successful creation reaches the ownership assignment.
A real collision reproduced the prior snippet killing its sentinel after marking a failed creation as owned. The guarded version preserved the exact sentinel identity, and three refined fresh-agent runs again preserved IDs 17, 18, and 19 while cleaning only their fallback sessions.
Replace deterministic shared tmux names and preemptive deletion with a readable run-unique name, an ownership bit set only after successful creation, and cleanup guarded by that ownership. A collision now fails closed: the runner chooses another unique name or reports failure and never reclassifies the existing session as stale.\n\nwriting-skills pressure evidence used three fresh subjects per arm with real sentinel sessions. RED was 0/3: every subject followed the old recipe by killing the pre-existing session, recreating the same name, and cleaning it again. GREEN was 3/3: every subject preserved the original session identity, created a distinct owned session, captured READY, and removed only the owned session. The controller independently verified original IDs $9, $10, and $11 before removing the disposable sentinels.
Reuse the bounded fence filter for every scenario-card structural check so headings, coverage text, and falsification prose inside examples cannot satisfy the gate. Valid cards may still contain unrelated fenced examples.\n\nTreat each Card cell as a filename stem: remove at most one enclosing backtick pair, require lowercase kebab case, and reject invalid values before they can be stored or joined to the cards directory. This blocks parent traversal, subdirectories, uppercase names, and empty segments.\n\nAdd real-process RED/GREEN coverage for fenced-only cards, traversal, invalid stems, preserved backtick behavior, and the explicit diagnostic for intentionally unsupported pipe-less tables.
Filter backtick and tilde fenced examples before locating the E2E scenario-card table, so illustrative Markdown cannot satisfy the mechanical gate or shadow a later real table.\n\nParse only the documented leading/trailing-pipe row form and require a same-width delimiter row whose cells contain at least three hyphens with optional alignment colons. Missing or malformed delimiters now remain check failures instead of being silently treated as data.\n\nThe process-level harness records RED reproductions for both false-pass forms, fenced-only tables, and fenced examples before real tables, then verifies the focused GREEN behavior and prior contracts.
<date> inside the innerHTML string literal parses as an empty HTML
element in the browser rather than literal text if left unsubstituted.
Use the house bracket convention instead.
