cad-capturelisted

<objective> Get a thought out of your head and into the right place without derailing. Three kinds, landing in `.planning/CAPTURE.md` - or, with `--cadence`, in Cadence's own queue (step 4), because friction with CADENCE noticed while working on somebody else's project has to leave that project to reach Cadence: - **todo** - an actionable item, tagged to a phase, so it resurfaces where it matters. This is the phase-linked queue mem-* lacks and the reason this exists. - **seed** - an idea for a future phase or milestone, parked in the backlog. - **note** - a free note; lands in the file like the rest. With `memory.backend: builtin` (the default) the note becomes recallable - it is still written here, `builtin` only reads `.planning/` back, never relocates the write. </objective> <process> 1. **Parse** `$ARGUMENTS`: leading `todo | seed | note` (default `todo` if omitted), the text, an optional `--phase N`, and an optional `--cadence` - this note is about CADENCE, not about the project you are in, so it goes to step 4 instead of steps 2-3. If a todo has no `--phase`, default to the current phase from the STATE cursor (`cursor get`); if the cursor is absent or unparseable, capture it unphased - pass no `--phase` at all - rather than guessing a phase or stopping. Under `--cadence` skip the cursor: a phase number belongs to this project's roadmap and means nothing in Cadence's queue. 2. **Capture through the seam** - one call, and the only way thi