feat(provider): memory plane — SQLite+sqlite-vec store + dev shell

The second plane of ratatoskr's Tier-3 Bifrost consumer: a durable memory
store Worldtree writes agent memory chunks into (upsert_many) and recalls
by vector similarity (search), with point reads + deletes. Implements
bifrost's own MemoryDataStore Protocol; conformance is #195 parity vs
InMemoryMemoryStore through the real dispatch_memory_call.

Store (memory_store.py): open_memory_store, describe_store, upsert_many
(replay/conflict idempotency, optimistic locking, injection rule, atomic
batch), search (cosine over sqlite-vec vec0, scope isolation INV-005,
over-fetch-then-filter so top_k counts in-scope), get/get_many,
delete_many, build_memory_provider_app. Dev shell (serve_memory.py):
ratatoskr-memory-provider entrypoint, port 8391.

TDD + heid-code-review (panel Groa/Hulda/Regin, zero true drift). Adopted
fixups: scope_filter dict guard, top_k<=0 -> [], stronger scope-isolation
+ delete-hit-search + handshake-POST tests. Partial-map optimistic-lock
semantics pinned against the reference via a new expected_revisions
parity test.

26 memory + 4 serve tests; #195 parity (upsert/search/expected_revisions)
green; ruff clean. Deps: +sqlite-vec.

uv.lock

@@ -1052,7 +1052,7 @@ wheels = [
 
 [[package]]
 name = "ratatoskr"
-version = "0.17.2"
+version = "0.17.3"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },
@@ -1075,6 +1075,7 @@ dev = [
 provider = [
     { name = "bifrost" },
     { name = "jsonschema" },
+    { name = "sqlite-vec" },
     { name = "starlette" },
     { name = "uvicorn", extra = ["standard"] },
 ]
@@ -1097,6 +1098,7 @@ requires-dist = [
     { name = "ratatoskr", extras = ["web"], marker = "extra == 'provider'" },
     { name = "respx", marker = "extra == 'dev'", specifier = ">=0.21" },
     { name = "ruff", marker = "extra == 'dev'", specifier = ">=0.6" },
+    { name = "sqlite-vec", marker = "extra == 'provider'", specifier = ">=0.1.6" },
     { name = "starlette", marker = "extra == 'web'", specifier = ">=0.40" },
     { name = "textual", specifier = ">=0.85" },
     { name = "textual-dev", marker = "extra == 'dev'", specifier = ">=1.5" },
@@ -1278,6 +1280,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/9b/36/9c015cd052fca743dae8cb2aeb16b551444787467db42ceab0fc968865af/ruff-0.15.13-py3-none-win_arm64.whl", hash = "sha256:2471da9bd1068c8c064b5fd9c0c4b6dddffd6369cb1cd68b29993b1709ff1b21", size = 11179336 },
 ]
 
+[[package]]
+name = "sqlite-vec"
+version = "0.1.9"
+source = { registry = "https://pypi.org/simple" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/68/85/9fad0045d8e7c8df3e0fa5a56c630e8e15ad6e5ca2e6106fceb666aa6638/sqlite_vec-0.1.9-py3-none-macosx_10_6_x86_64.whl", hash = "sha256:1b62a7f0a060d9475575d4e599bbf94a13d85af896bc1ce86ee80d1b5b48e5fb", size = 131171 },
+    { url = "https://files.pythonhosted.org/packages/a4/3d/3677e0cd2f92e5ebc43cd29fbf565b75582bff1ccfa0b8327c7508e1084f/sqlite_vec-0.1.9-py3-none-macosx_11_0_arm64.whl", hash = "sha256:1d52e30513bae4cc9778ddbf6145610434081be4c3afe57cd877893bad9f6b6c", size = 165434 },
+    { url = "https://files.pythonhosted.org/packages/00/d4/f2b936d3bdc38eadcbd2a87875815db36430fab0363182ba5d12cd8e0b51/sqlite_vec-0.1.9-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:4e921e592f24a5f9a18f590b6ddd530eb637e2d474e3b1972f9bbeb773aa3cb9", size = 160076 },
+    { url = "https://files.pythonhosted.org/packages/6f/ad/6afd073b0f817b3e03f9e37ad626ae341805891f23c74b5292818f49ac63/sqlite_vec-0.1.9-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.manylinux1_x86_64.whl", hash = "sha256:1515727990b49e79bcaf75fdee2ffc7d461f8b66905013231251f1c8938e7786", size = 163388 },
+    { url = "https://files.pythonhosted.org/packages/42/89/81b2907cda14e566b9bf215e2ad82fc9b349edf07d2010756ffdb902f328/sqlite_vec-0.1.9-py3-none-win_amd64.whl", hash = "sha256:4a28dc12fa4b53d7b1dced22da2488fade444e96b5d16fd2d698cd670675cf32", size = 292804 },
+]
+
 [[package]]
 name = "starlette"
 version = "1.1.0"