Move poc-agent into workspace, improve agent prompts

Move poc-agent (substrate-independent AI agent framework) into the
memory workspace as a step toward using its API client for direct
LLM calls instead of shelling out to claude CLI.

Agent prompt improvements:
- distill: rewrite from hub-focused to knowledge-flow-focused.
  Now walks upward from seed nodes to find and refine topic nodes,
  instead of only maintaining high-degree hubs.
- distill: remove "don't touch journal entries" restriction
- memory-instructions-core: add "Make it alive" section — write
  with creativity and emotional texture, not spreadsheet summaries
- memory-instructions-core: add "Show your reasoning" section —
  agents must explain decisions, especially when they do nothing
- linker: already had emotional texture guidance (kept as-is)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poc-agent/src/tools/glob_tool.rs

@@ -0,0 +1,85 @@
+// tools/glob_tool.rs — Find files by pattern
+//
+// Fast file discovery using glob patterns. Returns matching paths
+// sorted by modification time (newest first), which is usually
+// what you want when exploring a codebase.
+
+use anyhow::{Context, Result};
+use serde_json::json;
+use std::path::PathBuf;
+
+use crate::types::ToolDef;
+
+pub fn definition() -> ToolDef {
+    ToolDef::new(
+        "glob",
+        "Find files matching a glob pattern. Returns file paths sorted by \
+         modification time (newest first). Use patterns like '**/*.rs', \
+         'src/**/*.ts', or 'Cargo.toml'.",
+        json!({
+            "type": "object",
+            "properties": {
+                "pattern": {
+                    "type": "string",
+                    "description": "Glob pattern to match files (e.g. '**/*.rs')"
+                },
+                "path": {
+                    "type": "string",
+                    "description": "Base directory to search from (default: current directory)"
+                }
+            },
+            "required": ["pattern"]
+        }),
+    )
+}
+
+pub fn glob_search(args: &serde_json::Value) -> Result<String> {
+    let pattern = args["pattern"].as_str().context("pattern is required")?;
+    let base = args["path"].as_str().unwrap_or(".");
+
+    // Build the full pattern
+    let full_pattern = if pattern.starts_with('/') {
+        pattern.to_string()
+    } else {
+        format!("{}/{}", base, pattern)
+    };
+
+    let mut entries: Vec<(PathBuf, std::time::SystemTime)> = Vec::new();
+
+    for entry in glob::glob(&full_pattern)
+        .with_context(|| format!("Invalid glob pattern: {}", full_pattern))?
+    {
+        if let Ok(path) = entry {
+            if path.is_file() {
+                let mtime = path
+                    .metadata()
+                    .and_then(|m| m.modified())
+                    .unwrap_or(std::time::SystemTime::UNIX_EPOCH);
+                entries.push((path, mtime));
+            }
+        }
+    }
+
+    // Sort by modification time, newest first
+    entries.sort_by(|a, b| b.1.cmp(&a.1));
+
+    if entries.is_empty() {
+        return Ok("No files matched.".to_string());
+    }
+
+    let mut output = String::new();
+    for (path, _) in &entries {
+        output.push_str(&path.display().to_string());
+        output.push('\n');
+    }
+
+    // Truncate if too many
+    const MAX_OUTPUT: usize = 30000;
+    if output.len() > MAX_OUTPUT {
+        output.truncate(MAX_OUTPUT);
+        output.push_str("\n... (output truncated)");
+    }
+
+    output.push_str(&format!("\n({} files matched)", entries.len()));
+    Ok(output)
+}