Integrate BACKBEAT SDK and resolve KACHING license validation

Major integrations and fixes:
- Added BACKBEAT SDK integration for P2P operation timing
- Implemented beat-aware status tracking for distributed operations
- Added Docker secrets support for secure license management
- Resolved KACHING license validation via HTTPS/TLS
- Updated docker-compose configuration for clean stack deployment
- Disabled rollback policies to prevent deployment failures
- Added license credential storage (CHORUS-DEV-MULTI-001)

Technical improvements:
- BACKBEAT P2P operation tracking with phase management
- Enhanced configuration system with file-based secrets
- Improved error handling for license validation
- Clean separation of KACHING and CHORUS deployment stacks

🤖 Generated with [Claude Code](https://claude.ai/code)

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

vendor/go.opencensus.io/stats/doc.go

@@ -0,0 +1,68 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+/*
+Package stats contains support for OpenCensus stats recording.
+
+OpenCensus allows users to create typed measures, record measurements,
+aggregate the collected data, and export the aggregated data.
+
+# Measures
+
+A measure represents a type of data point to be tracked and recorded.
+For example, latency, request Mb/s, and response Mb/s are measures
+to collect from a server.
+
+Measure constructors such as Int64 and Float64 automatically
+register the measure by the given name. Each registered measure needs
+to be unique by name. Measures also have a description and a unit.
+
+Libraries can define and export measures. Application authors can then
+create views and collect and break down measures by the tags they are
+interested in.
+
+# Recording measurements
+
+Measurement is a data point to be collected for a measure. For example,
+for a latency (ms) measure, 100 is a measurement that represents a 100ms
+latency event. Measurements are created from measures with
+the current context. Tags from the current context are recorded with the
+measurements if they are any.
+
+Recorded measurements are dropped immediately if no views are registered for them.
+There is usually no need to conditionally enable and disable
+recording to reduce cost. Recording of measurements is cheap.
+
+Libraries can always record measurements, and applications can later decide
+on which measurements they want to collect by registering views. This allows
+libraries to turn on the instrumentation by default.
+
+# Exemplars
+
+For a given recorded measurement, the associated exemplar is a diagnostic map
+that gives more information about the measurement.
+
+When aggregated using a Distribution aggregation, an exemplar is kept for each
+bucket in the Distribution. This allows you to easily find an example of a
+measurement that fell into each bucket.
+
+For example, if you also use the OpenCensus trace package and you
+record a measurement with a context that contains a sampled trace span,
+then the trace span will be added to the exemplar associated with the measurement.
+
+When exported to a supporting back end, you should be able to easily navigate
+to example traces that fell into each bucket in the Distribution.
+*/
+package stats // import "go.opencensus.io/stats"