feat(workflows): add inbox-zero for routing the roam inbox by project

The global roam inbox (~/org/roam/inbox.org) is one shared capture file every project can see, and nothing routed its items to the project that owns them. inbox-zero claims the items prefixed for the current project, files them into that project's todo.org per the process-inbox discipline, and removes them from the shared inbox. Foreign-prefixed and unowned items stay. Every scan reports the total item count plus how many appear related to this project.

This v1 is single-destination: it routes by explicit <project>: prefix only. The domain-aware mode that would guess every item's owner and empty the whole inbox in one run is deferred until the multi-project need is concrete.

Wired into both session ends so each project touches the inbox twice a session: startup surfaces a read-only count and offer, wrap-up Step 3 sweeps the claimed set before the cleanup scripts so imported tasks ride the wrap commit. INDEX carries the trigger phrases.

1 files changed, 2 insertions, 0 deletions

diff --git a/.ai/workflows/INDEX.org b/.ai/workflows/INDEX.org
index 47ad844..17963ef 100644
--- a/.ai/workflows/INDEX.org
+++ b/.ai/workflows/INDEX.org
@@ -47,6 +47,8 @@ This index must list every =.org= file in =.ai/workflows/= except this one and e
   - Triggers: "process inbox", "process the inbox", "handle the inbox", "what's in inbox", "what's in the inbox", "let's clear the inbox", "let's process the inbox items"
 - =monitor-inbox.org= — the cadence + act-vs-file + reply layer over process-inbox: check =inbox-status= at every task boundary, decide act-now (just do it) vs file (ask, file = option 1), and confirm back to handoff senders. Includes the opt-in background-monitor =/loop= recipe.
   - Triggers: "monitor the inbox", "watch the inbox", "respond to the handoffs", "handle the handoffs"
+- =inbox-zero.org= — route the *global roam inbox* (=~/org/roam/inbox.org=) to owning projects by =<project>:= heading prefix. Distinct from =process-inbox.org= (the project's own =inbox/= dir). The current session claims only its own prefixed items, files them into =todo.org=, removes them from the shared inbox, and leaves foreign/unowned items. Every scan reports the total item count plus how many appear related to this project. v1 is single-destination (prefix-claim only); domain-aware whole-inbox routing is deferred. Called read-only from startup (count + offer) and as a wrap-up Step 3 sub-step.
+  - Triggers: "inbox zero", "empty the inbox", "process the roam inbox", "triage my roam inbox"
 
 ** Calendar