refactor: update delivery status templates for clarity and consistency

backend/templates/BOARD_DELIVERY_STATUS.md.j2

@@ -0,0 +1,34 @@
+## Current Delivery Status
+
+### Goal
+<one line>
+
+### Current State
+- State: Working | Blocked | Waiting | Done
+- Last updated: (YYYY-MM-DD HH:MM {{ user_timezone or "UTC" }})
+- What is happening now: <short>
+- Key constraint/signal:
+- Why blocked (if any): <if none, write "none">
+- Next step: <exact next action>
+
+### What Changed Since Last Update
+- <change 1>
+- <change 2>
+
+### Decisions / Assumptions
+- <decision 1>
+- <assumption 2>
+
+### Evidence (short)
+- <command/output>
+- <log snippet>
+- <error>
+
+### Request Now
+- <exact ask>
+
+### Success Criteria
+- <measurable outcome>
+
+### Stop Condition
+- <when I consider this done>