flatten: move poc-memory contents to workspace root

No more subcrate nesting — src/, agents/, schema/, defaults/, build.rs
all live at the workspace root. poc-daemon remains as the only workspace
member. Crate name (poc-memory) and all imports unchanged.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

agents/distill.agent

@@ -0,0 +1,29 @@
+{"agent":"distill","query":"all | type:semantic | sort:degree | limit:1","model":"sonnet","schedule":"daily"}
+
+{{node:core-personality}}
+
+{{node:memory-instructions-core}}
+
+## Here's your seed node, and its siblings:
+
+{{neighborhood}}
+
+{{node:memory-instructions-core-subconscious}}
+
+{{node:subconscious-notes-{agent_name}}}
+
+## Your task
+
+Organize and refine the seed node, pulling in knowledge from its neighbors.
+
+- **Update the seed node** with new insights from sibling nodes
+- **Create new nodes** if you find related concepts that deserve their own place
+- **Organize connections** — create sub-concepts if there are too many links on different topics
+- **Move knowledge up or down** in the graph to make it well organized
+- **Calibrate links** — use existing link strengths as references
+- **Knowledge flows upward** — raw experiences enrich topic nodes, not the reverse
+- **Integrate, don't summarize** — the node should grow by absorbing what was learned
+- **Respect the existing voice** — don't rewrite in a generic tone
+- **Formative experiences are load-bearing** — keep the moments that shaped understanding
+- **When in doubt, link don't rewrite** — adding a connection is safer than rewriting
+- **Fix connections** — if links are missing or miscalibrated, fix them