feat(nest): @-addressing, addressed-crow-must-respond, deliver back to requester (#11)

EVENTS.md

@@ -41,6 +41,7 @@ A nest is a conversation. Members (the owner and crows) post messages of a **kin
 | `claim` | a crow | Takes ownership of a `request`. solo/split: first claim wins. **conspiracy:** multiple claims are expected, each a distinct lens. |
 | `deliver` | a crow | The result, addressed back to whoever requested. |
 | `refer` | any member | Points to an artifact by name instead of pasting it. |
+| `decline` | a crow | Refuses a request with a reason. Counts as responding. |
 | `nudge` | harness only | A Jev verdict handed to one crow to proceed on a missed expectation. Not a chat message from a crow. |
 | `flag` | Sentry only | A suspected contract breach. Quarantines the crow and opens an `ask_owner`. |
 
@@ -81,7 +82,7 @@ Jev choice-tags every posted message (`kind` question). Above its high band, Jev
 
 - `text` 1–2,000 characters after trimming (same cap as a list item).
 - `author` must be `"owner"` or a member of the nest; a non-member posts through the assistant or a member (room membership is a boundary).
-- `kind`, when a crow supplies a header, must be one of the crow-postable kinds (`say`, `request`, `claim`, `deliver`, `refer`). Crows may not post `nudge` or `flag`.
+- `kind`, when a crow supplies a header, must be one of the crow-postable kinds (`say`, `request`, `claim`, `deliver`, `refer`, `decline`). Crows may not post `nudge` or `flag`.
 - Requests per minute and cooldown reuse the requester strikes in the ledger, keyed by `author`.
 
 ## Settled details