chore: replace short JWT_SECRET defaults with ≥32-char value

[chrip]

Context

Companion PR to Euro-Office/document-server-integration#13. Both PRs must be merged together — this PR bumps the document-server-integration submodule pointer to the commit in that PR.

The EuroOffice connector v11+ enforces a minimum JWT secret length of 32 characters. Short defaults in example commands and the orchestrated entrypoint fallback cause an immediate runtime error: "JWT secret key is too short (minimum 32 characters required)".

What changes

• README.md — docker run example secret updated to ≥32 chars
• build/scripts/orchestrated/docker-entrypoint.sh — ${JWT_SECRET:=secret} fallback raised to 35 chars
• build/scripts/orchestrated/example-docker-entrypoint.sh — same
• document-server-integration — submodule bumped to chore: replace short JWT_SECRET examples with ≥32-char value document-server-integration#13

Assisted-by: ClaudeCode:claude-sonnet-4-6

[MonaAghili]

Verified against both PR branches directly (not just the diffs).

Correctness: the touched paths do fix the crash — both new literals are ≥32 chars (my_long_jwt_secret_at_least_32_chars = 36, euro-office-dev-jwt-secret-key-2026 = 35).

Two things worth resolving before merge:

1. #13's sweep is incomplete. git diff main pr13 --name-only shows only 9 files changed, but these still have secrets under 32 chars and will still reproduce the original error:

   • web/documentserver-example/nodejs/config/default.json:37 — "secret": "secret". This is what node-config actually loads when NODE_CONFIG isn't set (e.g. local npm start outside Docker).
   • web/documentserver-example/csharp/README.md:47, csharp-mvc/README.md:46 — value="secret".
   • nodejs/README.md:55,176 inline JSON examples, plus the documented-default tables in php, php-laravel, python, ruby READMEs — all still show secret / your-256-bit-secret.

2. This trades a loud failure for a silent one. DocumentServer's production docker-entrypoint.sh enables JWT by default (JWT_ENABLED:=true). Previously, forgetting to set JWT_SECRET crashed immediately — an accidental safety net. Now the fallback is long enough to pass validation, so that same misconfiguration starts up fine, silently signing with a secret that's public in this repo's git history. Worth either failing startup when JWT_ENABLED=true and JWT_SECRET is unset, or at least logging a loud warning when the fallback is used.

No other issues — quoting/expansion in the entrypoint scripts is unchanged, and the submodule bump points at exactly #13's head commit with nothing extra riding along.