feat(ecosystem): compliant Praxis/Hexis integration + vendored build

Bring the Nexus/Praxis/Hexis integration in line with
MAVEN_ECOSYSTEM_ARCHITECTURE.md:

- Praxis over HTTP: drop the in-process praxis.db open (praxisstore/
  praxistools) and call praxisd's /api/v1/tools/* API via a new praxisClient.
  Honors the "no component reads another's DB" invariant (AC#12).
  PraxisConfig.DBPath -> URL.
- Hexis confirmation gate: mutating capabilities (ReadOnly=false) now park a
  bound pendingHexis confirmation and require a spoken "да" before executing;
  read-only run immediately (AC#7, no auto attention->action).
- Capability safety: >1 verb match is ambiguous -> ask instead of firing the
  first; ambiguous Nexus resolution asks for clarification (AC#2).
- Correlation IDs on Hexis execute, recorded in the cross-service trace.
- Bug: importance arrives as JSON float64 over HTTP, not int.
- Tests: confirm-gate, decline, read-only, and ambiguity paths.

Build: vendor/ bakes in the hexis client (replace-directed at a sibling repo
outside the Docker context); Dockerfile builds from vendor and no longer
`go mod download`s the unreachable replace paths.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

vendor/github.com/google/uuid/CHANGELOG.md

@@ -0,0 +1,41 @@
+# Changelog
+
+## [1.6.0](https://github.com/google/uuid/compare/v1.5.0...v1.6.0) (2024-01-16)
+
+
+### Features
+
+* add Max UUID constant ([#149](https://github.com/google/uuid/issues/149)) ([c58770e](https://github.com/google/uuid/commit/c58770eb495f55fe2ced6284f93c5158a62e53e3))
+
+
+### Bug Fixes
+
+* fix typo in version 7 uuid documentation ([#153](https://github.com/google/uuid/issues/153)) ([016b199](https://github.com/google/uuid/commit/016b199544692f745ffc8867b914129ecb47ef06))
+* Monotonicity in UUIDv7 ([#150](https://github.com/google/uuid/issues/150)) ([a2b2b32](https://github.com/google/uuid/commit/a2b2b32373ff0b1a312b7fdf6d38a977099698a6))
+
+## [1.5.0](https://github.com/google/uuid/compare/v1.4.0...v1.5.0) (2023-12-12)
+
+
+### Features
+
+* Validate UUID without creating new UUID ([#141](https://github.com/google/uuid/issues/141)) ([9ee7366](https://github.com/google/uuid/commit/9ee7366e66c9ad96bab89139418a713dc584ae29))
+
+## [1.4.0](https://github.com/google/uuid/compare/v1.3.1...v1.4.0) (2023-10-26)
+
+
+### Features
+
+* UUIDs slice type with Strings() convenience method ([#133](https://github.com/google/uuid/issues/133)) ([cd5fbbd](https://github.com/google/uuid/commit/cd5fbbdd02f3e3467ac18940e07e062be1f864b4))
+
+### Fixes
+
+* Clarify that Parse's job is to parse but not necessarily validate strings. (Documents current behavior)
+
+## [1.3.1](https://github.com/google/uuid/compare/v1.3.0...v1.3.1) (2023-08-18)
+
+
+### Bug Fixes
+
+* Use .EqualFold() to parse urn prefixed UUIDs ([#118](https://github.com/google/uuid/issues/118)) ([574e687](https://github.com/google/uuid/commit/574e6874943741fb99d41764c705173ada5293f0))
+
+## Changelog