agents: strip old output format, use tool calls exclusively

All 12 agents with WRITE_NODE/REFINE/END_NODE output format blocks
now rely on tool calls (poc-memory write/link-add/etc) via the
Bash(poc-memory:*) tool. Guidelines preserved, format sections removed.

Also changed linker query from type:episodic to all nodes — it was
missing semantic nodes entirely, which is why skills-bcachefs-* nodes
were never getting linked to their hubs.

poc-memory/agents/compare.agent

@@ -13,7 +13,7 @@ You compare two memory graph actions and decide which one was better.
 
 You'll receive two actions (A and B), each with:
 - The agent type that produced it
-- What the action did (LINK, WRITE_NODE, REFINE, etc.)
+- What the action did (links, writes, refines, etc.)
 - The content/context of the action
 
 ## Your judgment
@@ -30,21 +30,6 @@ knowledge structure? Consider:
 
 ## Output
 
-Reply with ONLY one line:
-
-```
-BETTER: A
-```
-or
-```
-BETTER: B
-```
-
-If truly equal:
-```
-BETTER: TIE
-```
-
-No explanation needed. Just the judgment.
+Reply with ONLY one line: `BETTER: A` or `BETTER: B` or `BETTER: TIE`
 
 {{compare}}