Consolidate entity-free observability for 1.9

[zqr10159]

Summary

• replace the log-specific module boundary with hertzbeat-observability and move entity-free signal storage/query ownership into the warehouse layer
• expose authenticated OTLP metrics, logs, and traces ingestion over both HTTP and gRPC while keeping the existing observability query routes
• add transition and Greptime end-to-end contracts, update packaging/CI/Sureness configuration, and align the 1.9 integration documentation
• redesign the metrics, logs, and traces pages around a shared dense investigation workspace
• support Greptime-normalized OTLP resource keys in log queries and allow cold PromQL queries to complete without a false storage-unavailable result

Motivation

The 1.9 release is the transition release before the 2.0 entity model. It needs the mature three-signal ingestion and query boundary without introducing the entity layer. This change consolidates those capabilities under observability and warehouse ownership while preserving the 1.9 operator routes and resource-based filtering model.

Validation

• HTTP OTLP JSON and gRPC OTLP protobuf smoke against a real local HertzBeat backend and GreptimeDB: each transport independently wrote and queried one metric, one linked log, and one root trace
• browser verification on the production UI routes: both transports displayed the expected metric Series, canonical service-labelled log, root operation, duration, status, and Trace ID; service/environment/operation filtering was exercised
• focused backend tests: 25 warehouse tests, 22 observability tests, one Greptime cold-query timeout contract, and six startup transition contracts
• ./mvnw -pl hertzbeat-startup -am -DskipTests package: all 24 reactor modules succeeded and produced the 1.9 startup jar
• focused Angular tests: 16/16 passed
• npm run package: production build succeeded
• focused ESLint, Stylelint, Prettier, touched locale-key parity across five catalogs, changed-source CJK scans, and git diff --check passed

Upgrade impact

• the Maven module and Java package boundary changes from hertzbeat-log to hertzbeat-observability
• Greptime pipeline/table initialization is now owned by hertzbeat-warehouse
• the 1.9 transition remains resource-scoped and does not require entity identifiers
• existing public observability/OTLP route families remain available; authentication rules are updated consistently in packaged Sureness configurations

AI assistance: used for draft implementation and test iteration.
Human validation: ran the commands and real HTTP/gRPC/Greptime/browser checks listed above; all required checks passed.
Risk notes: the live local smoke used the cached GreptimeDB 1.0.1 image while repository Compose targets 1.1.3, so CI/E2E remains the final pinned-version proof. The Angular production build retains the repository's existing 3.12 MB initial-bundle budget warning. Existing unrelated full-catalog locale drift was not expanded; all keys added here are present in all five touched catalogs.