feat(sources v1): the agent locates files itself — ls/find/grep + tool-call cards

User pivot (2026-09-19): no attachments UI at all. Pasting paths is native
for technical users and alien for everyone else - so the agent gets the
tools to find what the learner merely NAMES. The learner communicates in
messages; the agent locates and reads. Zero cross-stream seams: paths
already live in tool parts, so the sources "list" is the transcript.

- ls/find/grep: pi-verbatim schemas, descriptions, and output formats
  (fd's glob semantics, rg's path:line: match format, pi's truncation
  notices), ported to pure Node - no binaries, no shell-out, read-only by
  construction. Deltas from pi: home-anchored resolution (the harness has
  no cwd), .gitignore replaced by hard noise exclusions
  (node_modules/.git/Library/.Trash), 10s walk timeout with partial results.
- read: description swapped to pi-verbatim (doctrine moved to the prompt);
  relative paths now resolve against the learner's home like the rest.
- prompts/shared/05-learner-files.md: one minimal doctrine fragment
  composed into BOTH agents (composeInstructions grew a shared/ dir,
  before the agent's own fragments). teacher/30-jobs.md keeps only the
  pdf-dispatch addendum.
- ToolCallCard: the generic quiet tool-call card the user specced -
  collapsed one-liner (tool name + headline argument), expandable to full
  input/output, errors red, image payloads never render. Registered for
  read/ls/find/grep.
- ui-message.ts: TeacherUITools entries for the four tools (mechanical).
- tests: fs-tools suite (glob semantics, pi formats, exclusions, limits),
  registry/card renders, shared-fragment composition pins, tool-registry
  key updates, read re-anchor.

tests/read-tool.test.ts

@@ -31,12 +31,17 @@ describe("read tool — text semantics", () => {
 		assert.equal(await run({ path: file }), "hello\nworld");
 	});
 
-	it("resolves relative paths against cwd", async () => {
-		fs.writeFileSync(path.join(process.cwd(), "lh-read-rel-test.txt"), "rel", "utf-8");
+	it("resolves relative paths against the learner's home (sources v1 anchoring)", async () => {
+		// sources v1: the harness has no meaningful cwd — "find my notes" must
+		// work from a bare relative path, so the home directory is the anchor
+		// (fs-shared resolveSourcePath). Scratch file in home, cleaned up.
+		const rel = `lh-read-rel-test-${process.pid}.txt`;
+		const homeFile = path.join(os.homedir(), rel);
+		fs.writeFileSync(homeFile, "rel", "utf-8");
 		try {
-			assert.equal(await run({ path: "lh-read-rel-test.txt" }), "rel");
+			assert.equal(await run({ path: rel }), "rel");
 		} finally {
-			fs.unlinkSync(path.join(process.cwd(), "lh-read-rel-test.txt"));
+			fs.unlinkSync(homeFile);
 		}
 	});