feat(claudewatcher): ingest Claude Code session transcripts into brain

New package internal/claudewatcher. The volume gate (24 turns/week of
agentsquad logs vs 500/week gate) exposed that the real signal lives
in daily Claude Code usage at ~/.claude/projects/*/<uuid>.jsonl, not
in agentsquad output. This package captures that signal. See infra#73
Track E + hyperguild#27 for the full reframe.

Components:
- parser: tolerant JSONL parser over the observed Claude Code session
  schema (user / assistant / attachment / system + bookkeeping types).
  Skip-flag fast-paths queue-operation, last-prompt, permission-mode,
  ai-title, bridge-session, file-history-snapshot.
- scrubber: 11-rule fail-closed regex set for credential shapes
  (bearer, postgres URIs, PEM, ssh-key, ghp_/sk-/sk-ant-/AKIA, homelab
  env tokens, SOPS markers). Drop turn + log on match.
- cursor: postgres-backed claude_session_cursors table, keyed by
  (host, file_path) with byte_offset. Resumable across pod restarts.
- watcher: poll loop. Walks SessionsDir, processes each .jsonl from
  its cursor offset, runs scrubber, emits a Batch per file to a
  Sink interface, advances cursor on successful Ingest.

No classifier integration in this commit — every kept turn is emitted
in a per-session batch. The cmd/server wiring (next commit) routes
batches to brain/wiki/claude-sessions/facts/. Classifier-driven hall
routing (decisions / failures / hypotheses) is a follow-up.

19 unit tests across parser + scrubber + watcher. task check green.

Refs: infra#73, hyperguild#27

ingestion/internal/claudewatcher/parser_test.go

@@ -0,0 +1,157 @@
+package claudewatcher
+
+import (
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func collect(t *testing.T, body string) ([]Turn, int64, error) {
+	t.Helper()
+	var out []Turn
+	end, err := ParseStream(strings.NewReader(body), 0, nil, func(tr Turn) error {
+		out = append(out, tr)
+		return nil
+	})
+	return out, end, err
+}
+
+func TestParseStream_UserTurnStringContent(t *testing.T) {
+	body := `{"type":"user","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":"hello world"}
+`
+	turns, end, err := collect(t, body)
+	require.NoError(t, err)
+	require.Len(t, turns, 1)
+	assert.Equal(t, "user", turns[0].Type)
+	assert.Equal(t, "S", turns[0].SessionID)
+	assert.Equal(t, "hello world", turns[0].Content)
+	assert.False(t, turns[0].Skip)
+	assert.Equal(t, int64(len(body)), end)
+}
+
+func TestParseStream_UserTurnContentBlocks(t *testing.T) {
+	body := `{"type":"user","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":{"role":"user","content":[{"type":"text","text":"line 1"},{"type":"text","text":"line 2"}]}}
+`
+	turns, _, err := collect(t, body)
+	require.NoError(t, err)
+	require.Len(t, turns, 1)
+	assert.Equal(t, "line 1\nline 2", turns[0].Content)
+}
+
+func TestParseStream_AssistantToolUse(t *testing.T) {
+	body := `{"type":"assistant","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":{"content":[{"type":"text","text":"calling now"},{"type":"tool_use","name":"Edit","input":{}}]}}
+`
+	turns, _, err := collect(t, body)
+	require.NoError(t, err)
+	require.Len(t, turns, 1)
+	assert.Equal(t, "Edit", turns[0].ToolName)
+	assert.Contains(t, turns[0].Content, "calling now")
+	assert.Contains(t, turns[0].Content, "[tool_use:Edit]")
+}
+
+func TestParseStream_AssistantToolResult(t *testing.T) {
+	body := `{"type":"user","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":{"content":[{"type":"tool_result","content":"output of cmd"}]}}
+`
+	turns, _, err := collect(t, body)
+	require.NoError(t, err)
+	require.Len(t, turns, 1)
+	assert.Contains(t, turns[0].Content, "[tool_result] output of cmd")
+}
+
+func TestParseStream_SkipsBookkeepingTypes(t *testing.T) {
+	body := strings.Join([]string{
+		`{"type":"queue-operation","sessionId":"S","content":"x"}`,
+		`{"type":"last-prompt","sessionId":"S","lastPrompt":"y"}`,
+		`{"type":"permission-mode","sessionId":"S","permissionMode":"auto"}`,
+		`{"type":"ai-title","sessionId":"S","aiTitle":"My session"}`,
+		`{"type":"file-history-snapshot","messageId":"abc"}`,
+	}, "\n") + "\n"
+	turns, _, err := collect(t, body)
+	require.NoError(t, err)
+	require.Len(t, turns, 5)
+	for _, tr := range turns {
+		assert.True(t, tr.Skip, "expected Skip=true for %q", tr.Type)
+	}
+}
+
+func TestParseStream_UnknownTypeIsSkip(t *testing.T) {
+	body := `{"type":"future-thing","sessionId":"S"}` + "\n"
+	turns, _, err := collect(t, body)
+	require.NoError(t, err)
+	require.Len(t, turns, 1)
+	assert.True(t, turns[0].Skip)
+}
+
+func TestParseStream_MalformedLineIsSkippedNotFatal(t *testing.T) {
+	body := strings.Join([]string{
+		`{"type":"user","sessionId":"S","message":"first"}`,
+		`{not valid json`,
+		`{"type":"user","sessionId":"S","message":"third"}`,
+	}, "\n") + "\n"
+	var warnings int
+	var turns []Turn
+	_, err := ParseStream(strings.NewReader(body), 0, func(format string, args ...any) {
+		warnings++
+	}, func(tr Turn) error {
+		turns = append(turns, tr)
+		return nil
+	})
+	require.NoError(t, err)
+	require.Len(t, turns, 2, "first + third should make it through")
+	assert.Equal(t, 1, warnings)
+}
+
+func TestParseStream_EmitErrStopHaltsCleanly(t *testing.T) {
+	body := strings.Join([]string{
+		`{"type":"user","sessionId":"S","message":"a"}`,
+		`{"type":"user","sessionId":"S","message":"b"}`,
+		`{"type":"user","sessionId":"S","message":"c"}`,
+	}, "\n") + "\n"
+	count := 0
+	end, err := ParseStream(strings.NewReader(body), 0, nil, func(tr Turn) error {
+		count++
+		if count == 2 {
+			return ErrStop
+		}
+		return nil
+	})
+	require.NoError(t, err)
+	assert.Equal(t, 2, count)
+	assert.Greater(t, end, int64(0))
+}
+
+func TestParseStream_EmitOtherErrorPropagates(t *testing.T) {
+	body := `{"type":"user","sessionId":"S","message":"a"}` + "\n"
+	want := errors.New("boom")
+	_, err := ParseStream(strings.NewReader(body), 0, nil, func(tr Turn) error {
+		return want
+	})
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "boom")
+}
+
+func TestParseStream_AttachmentHookEvent(t *testing.T) {
+	body := `{"type":"attachment","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","attachment":{"type":"hook_success","hookName":"SessionStart:startup","hookEvent":"SessionStart","content":"hook body"}}
+`
+	turns, _, err := collect(t, body)
+	require.NoError(t, err)
+	require.Len(t, turns, 1)
+	assert.Equal(t, "hook body", turns[0].Content)
+}
+
+func TestParseStream_OffsetAdvances(t *testing.T) {
+	body := `{"type":"user","sessionId":"S","message":"a"}` + "\n" +
+		`{"type":"user","sessionId":"S","message":"b"}` + "\n"
+	var offsets []int64
+	_, err := ParseStream(strings.NewReader(body), 100, nil, func(tr Turn) error {
+		offsets = append(offsets, tr.OffsetAfter)
+		return nil
+	})
+	require.NoError(t, err)
+	require.Len(t, offsets, 2)
+	assert.Greater(t, offsets[0], int64(100))
+	assert.Greater(t, offsets[1], offsets[0])
+}