spikelisted

Validate the single highest-risk low-level technical assumption before locking in low-level design. $ARGUMENTS may be: - A freeform description of the assumption to validate, or - `--lld <path>` to scan a referenced LLD's `[PENDING SPIKE VALIDATION]` tags and pick the highest-risk one automatically, or - `--hld <path>` to do the same directly against an HLD — use this when the risky assumption was flagged (e.g. via `/add-spike`) before any LLD exists yet, or - Nothing at all — infer the doc from this conversation (see step 1) if one is clearly in context. If $ARGUMENTS is empty and no HLD/LLD path can be inferred from this conversation, ask the user to provide a description or a design doc path and stop. Steps: 1. Identify the single highest-risk or lowest-level unvalidated assumption to test: - If a freeform description was given, use it directly. - If `--lld <path>` or `--hld <path>` was given, read the file at `<path>` (stop and tell the user if it does not exist) and scan it for `[PENDING SPIKE VALIDATION]` tags. - If $ARGUMENTS is empty (no description, no `--hld`/`--lld` flag), look back through this conversation for HLD/LLD paths already established (created via `/hld`/`/lld`, or referenced by an earlier `/spike`, `/add-spike`, `/resolve-open-questions`, `/implement-lld`, or `/reconcile` call in this session). If exactly one design doc with an outstanding `[PENDING SPIKE VALIDATION]` tag is found, confirm it with the user before proceeding. If more than o