fix(connector): complete the 16 incomplete connector implementations - #5394

…rsion

Sync from apache/eventmesh develop docs/feature/connectors (the docs
folded into PR apache/eventmesh#5394). Website adaptations:
- README.md renamed to connectors.md (versioned_docs convention)
- sidebar_position frontmatter on every page; category at 6.5
- internal links rebased one level deeper (feature/connectors/)
- documentation-map.md gains the Connectors bullet

Bring the single source of truth up to date with what actually landed:

- SSE / WS push: unified ACK-tracked redelivery + DLQ now shared with
  long-polling via ReliableDispatcher; real-broker e2e suite in #5389
- Connector Runtime: all 23 plugins fully implemented since #5394 (the
  "rest are templates" note is stale); unit tests still cover only
  file/kafka/pulsar/rocketmq
- A2A: task reaper + Meta-backed agent cards landed in #5346, quota
  classification in #5373; Beta promotion gated on Testcontainers E2E
  (#5340) instead of "pending" items
- add the memory storage backend row (default, zero-dependency dev/CI;
  #5400) and mention it in the features list, both languages

…in, A2A to 10108, 10205 gRPC reserved

8080/8081 collide with the most common dev-service ports (Tomcat, Jenkins,
Spring Boot apps, proxies). Move back onto the project's own 1.x default
port block, which keeps long-time users on familiar numbers:/n
- traffic HTTP 8080 -> 10105 (all app protocols multiplex on it, incl.
  the legacy /eventmesh/* bridge)
- admin HTTP    8081 -> 10106
- WebSocket     8082 -> 10107 (opt-in, unchanged default -1)
- A2A Gateway   10105 -> 10108 (frees 10105 for the CORE runtime; the
  experimental gateway takes the adjacent 10108)
- 10205 documented as RESERVED for a future gRPC protocol port (the 1.x
  default): the uni runtime does not ship a gRPC server yet, and the
  port must not be casually taken so a later gRPC addition lands on the
  historical number

Touched: EventMeshApplication defaults, bin/start.sh, docker/Dockerfile(+.connector),
K8s manifests + README, SDK CloudEventsClient default URL + javadocs, A2AClient /
ExampleConstants / A2AGatewayDemo, e2e test literals, docs (quickstart,
configuration, deployment, a2a) and eventmesh.properties comments.

Configuration keys are unchanged - only defaults move; existing
deployments pinning the old ports keep working.

Also point image-smoke-test.yml at the new ports throughout (host = container,
10105/10106 - no offset mapping left).

README / README.zh-CN quick-start port mentions updated too.

Feature docs swept too (client-java, pubsub, streaming, introduction, index,
admin-api, http-api, observability, connectors overview) - connector-local
webhook ports are untouched.

Fix a port-sweep typo (10100 -> 10105) in the documentation map.

README / README.zh-CN capability-status refreshed against the current tree:/n- SSE/WS push: ACK-tracked redelivery + DLQ shared with long-polling
  (ReliableDispatcher); e2e-real-broker suite in #5389
- Connector Runtime: all 23 plugins fully implemented since #5394 (no
  template stubs left); 4 of 23 still carry the only unit tests
- A2A Gateway: reaper + Meta-backed agent cards landed #5346, quota #5373;
  Beta promotion gated on Testcontainers E2E (#5340)
- new Memory storage row (Beta, zero-dependency dev/CI default, #5400)

…bility table (en/zh)

- Connector Runtime: 23 plugins complete since apache#5394, hardening in apache#5328
- A2A: the Testcontainers E2E promotion gate (apache#5340) closed 2026-09
- Recommendation wording Evaluate -> Usable; stale gate wording updated