Add storage stack modules and track them in git

The modules workspace previously ignored every path matching `storage-*`,
which kept all Hypercore, Hyperbee, Hyperdrive, and Autobase packages out
of version control. Narrow .gitignore to test-artifact patterns only so
production category trees are committed.

Storage packages (23 total):
- storage-hypercore (7): replicator, seed-policy, fork-picker, merkle-sync,
  priority-fetch, bitfield-scheduler, audit-chain
- storage-hyperbee (5): batch-write, diff-follow, range-watch,
  secondary-index, tombstone-gc
- storage-hyperdrive (6): entry-catalog, gc-sweep, mirror-sync, mount-bridge,
  version-snapshot, watch-notify
- storage-autobase (5): fork-choice, view-sync, writer-lease, indexer-bus,
  light-writer

Implementation highlights:
- Shared attach/gossip helpers in _shared/storage-gossip-base.js
- P2P modules use Protomux gossip via p2p-bare; local planners omit swarm
- Recent deepen pass: priority queues, batch caps, audit export/import,
  watch/notify aliases on range-watch, fork/view lease helpers, etc.
- Per-package README, docs/api.md, docs/architecture.md, tests, examples

Also update modules/README.md doc hub links for the full storage stack
(hypercore, hyperbee, hyperdrive, autobase).

Co-authored-by: Cursor <[email protected]>

storage-hypercore/hyper-p2p-core-audit-chain/test/test.js

@@ -0,0 +1,61 @@
+require('bare-process/global')
+const test = require('brittle')
+const { HyperP2PCoreAuditChain, PROTOCOL } = require('../index.js')
+
+const mockCore = { length: 3 }
+
+test('exports', (t) => {
+  t.ok(HyperP2PCoreAuditChain)
+  t.is(PROTOCOL, 'core-audit-chain/v1')
+})
+
+test('appendAudit verifyChain tail', async (t) => {
+  const m = new HyperP2PCoreAuditChain()
+  m.attach(mockCore)
+  m.appendAudit({ op: 'init' })
+  m.appendAudit({ op: 'write' })
+  const v = m.verifyChain()
+  t.ok(v.ok)
+  t.is(m.tail(1).length, 1)
+  t.is(m.tail(2).length, 2)
+  await m.close()
+})
+
+test('validation', async (t) => {
+  const m = new HyperP2PCoreAuditChain()
+  try { m.appendAudit(null) } catch (e) { t.ok(e) }
+  try { m.attach(null) } catch (e) { t.ok(e) }
+  try { m.tail(-1) } catch (e) { t.ok(e) }
+  await m.close()
+})
+
+test('getStats', async (t) => {
+  const m = new HyperP2PCoreAuditChain()
+  m.appendAudit({ x: 1 })
+  const s = m.getStats()
+  t.is(s.protocol, 'core-audit-chain/v1')
+  t.is(s.length, 1)
+  await m.close()
+})
+
+test('exportChain importChain', async (t) => {
+  const m = new HyperP2PCoreAuditChain()
+  m.appendAudit({ op: 'a' })
+  m.appendAudit({ op: 'b' })
+  const exported = m.exportChain()
+  const m2 = new HyperP2PCoreAuditChain()
+  const v = m2.importChain(exported)
+  t.ok(v.ok)
+  t.is(m2.getStats().length, 2)
+  await m.close()
+  await m2.close()
+})
+
+test('broken chain detected', async (t) => {
+  const m = new HyperP2PCoreAuditChain()
+  m.appendAudit({ a: 1 })
+  m._chain[0].hash = 'bad'
+  const v = m.verifyChain()
+  t.not(v.ok)
+  await m.close()
+})