docs: document -d flag and Docker process supervision model

[bitflicker64]

Purpose of the PR

• Part of [Bug] Docker containers never restart when Java process crashes — broken cron monitor + tail -f /dev/null supervision #3043 (Chunk 10)
• Follow-up to fix(pd,store): fg mode exit code propagation in startup scripts #3047 (added -d flag to PD/Store startup scripts) and fix(docker): supervise Java process in entrypoints instead of tail -f /dev/null #3051/chore(docker): add HEALTHCHECK & clean Dockerfiles #3052 (Docker entrypoint supervision + HEALTHCHECK)

Documents the new -d true|false daemon flag and the Docker-native process supervision model introduced in the preceding PRs.

Main Changes

hugegraph-pd/README.md:

• Add -d DAEMON to the startup options signature
• Document: daemon mode (true = daemon, false = foreground; default: true); set to false under Docker or a process supervisor

hugegraph-store/README.md:

• Same additions as PD

hugegraph-server/hugegraph-dist/docker/README.md:

• Add section explaining HEALTHCHECK endpoints (:8080/versions, :8620/v1/health, :8520/v1/health) and the Java process supervision model
• Note that the cron-based monitor (-m true) is for VM/bare-metal only, not Docker

Verifying these changes

• Need tests and can be verified as follows:
  • docker inspect <image> | grep -A5 Healthcheck — confirms HEALTHCHECK is present
  • docker stop <container> — container exits cleanly (SIGTERM forwarded to Java)
  • kill -9 <java-pid> inside container — container exits, restart policy fires

Does this PR potentially affect the following parts?

• Dependencies
• Modify configurations
• The public API
• Other affects
• Nope

Documentation Status

• Doc - Updated (in-repo README files only; hugegraph-doc follow-up is tracked separately)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 1.48%. Comparing base (39dfb2d) to head (97b197d).

❗ There is a different number of reports uploaded between BASE (39dfb2d) and HEAD (97b197d). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (39dfb2d)	HEAD (97b197d)
	2	1

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #3056       +/-   ##
============================================
- Coverage     34.89%   1.48%   -33.42%     
+ Complexity      338      21      -317     
============================================
  Files           803     781       -22     
  Lines         68241   65726     -2515     
  Branches       8965    8517      -448     
============================================
- Hits          23815     975    -22840     
- Misses        41826   64667    +22841     
+ Partials       2600      84     -2516     

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