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-hyperbee/hyper-p2p-bee-secondary-index/test/test.js

@@ -0,0 +1,38 @@
+require('bare-process/global')
+const test = require('brittle')
+const { HyperP2PBeeSecondaryIndex, PROTOCOL } = require('../index.js')
+
+test('exports', (t) => {
+  t.ok(HyperP2PBeeSecondaryIndex)
+  t.is(PROTOCOL, 'bee-secondary-index/v1')
+})
+
+test('indexPut indexLookup', async (t) => {
+  const m = new HyperP2PBeeSecondaryIndex()
+  m.attach({ get: async () => null })
+  m.indexPut('tag:a', 'pk-1')
+  m.indexPut('tag:a', 'pk-2')
+  t.is(m.indexLookup('tag:a').length, 2)
+  await m.close()
+})
+
+test('indexRemove', async (t) => {
+  const m = new HyperP2PBeeSecondaryIndex()
+  m.indexPut('s', 'p')
+  t.ok(m.indexRemove('s', 'p'))
+  t.is(m.indexLookup('s').length, 0)
+  await m.close()
+})
+
+test('validation', async (t) => {
+  const m = new HyperP2PBeeSecondaryIndex()
+  try { m.indexPut(null, 'p') } catch (e) { t.ok(e) }
+  await m.close()
+})
+
+test('rebuildIndex', async (t) => {
+  const m = new HyperP2PBeeSecondaryIndex()
+  const n = await m.rebuildIndex([{ secondaryKey: 'b', primaryKey: '1' }])
+  t.is(n, 1)
+  await m.close()
+})