chore(deps): repin bifrost==1.0.0 (first stable; wire v0.6 frozen)

Bifrost shipped 1.0.0 — first stable release, freezing wire v0.6 (the
surface ratatoskr's combined-builder consumer #18 already adopted).
Non-breaking: byte-identical on the wire to the prior >=0.10.0 pin.
Switched floor pin -> exact pin per the stable-substrate posture.
Suite 506 green against bifrost 1.0.0.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.18.1"
+version = "0.18.2"
 description = "Worldtree Conversation API debug TUI — multi-pane observability dashboard"
 readme = "README.md"
 requires-python = ">=3.12"
@@ -30,7 +30,7 @@ web = [
 # from the debug TUI. Recipe: bifrost/docs/implementing-a-consumer.md.
 provider = [
     "ratatoskr[web]",       # reuse the starlette + uvicorn ASGI stack
-    "bifrost>=0.10.0",      # consumer engines + library (0.10.0: build_combined_app (#18) + mandatory affect.fetch, strong-or-absent; 0.8.0/wire-v0.6: scope_all/scope_any split (#11); 0.7.0/v0.5: agent_self)
+    "bifrost==1.0.0",       # consumer engines + library. 1.0.0 = first STABLE release, wire v0.6 FROZEN (non-breaking repin from >=0.10.0; build_combined_app #18 + mandatory affect.fetch; 0.8.0/v0.6 scope_all/scope_any #11; 0.7.0/v0.5 agent_self)
     "jsonschema>=4",        # bifrost runtime dep — envelope validation
     "sqlite-vec>=0.1.6",    # vector index for the memory plane (vec0 virtual table)
 ]