config file, install command, scrub personal references

Add ~/.config/poc-memory/config.toml for user_name, assistant_name,
data_dir, projects_dir, and core_nodes. All agent prompts and
transcript parsing now use configured names instead of hardcoded
personal references.

`poc-memory daemon install` writes the systemd user service and
installs the memory-search hook into Claude's settings.json.

Scrubbed hardcoded names from code and docs.

Authors: ProofOfConcept <poc@bcachefs.org> and Kent Overstreet

src/bin/memory-search.rs

@@ -37,7 +37,7 @@ fn main() {
     }
 
     // Skip system/idle prompts
-    for prefix in &["Kent is AFK", "You're on your own", "IRC mention"] {
+    for prefix in &["is AFK", "You're on your own", "IRC mention"] {
         if prompt.starts_with(prefix) {
             return;
         }