feat: Add remote Tika parsing support

[arsaboo]

Description

This is a follow-up to #845.

This PR adds Apache Tika as a new document parsing engine. Tika is remote-only: it sends files to a configured tika-server via PUT /tika and writes the extracted text as Markdown, so no local install or model downloads are needed.

What's included:

• New deeptutor/services/parsing/engines/tika/ engine (config, remote client, adapter)
• Registered tika in the parser factory and runtime settings
• TIKA_SERVER_URL env override with default http://localhost:9998
• POST /api/v1/settings/document-parsing/tika/test endpoint for live connectivity checks
• Tika settings UI (server URL, test connection, save) in the document-parsing settings page
• Tests and README updates

Tested against a live Apache Tika 3.3.1 server (including Unicode filenames).

Related Issues

• Closes [Feature Request]: Add remote document parser (Docling/Tika) support #831
• Related to [Feature Request]: Add remote document parser (Docling/Tika) support #831

Module(s) Affected

• agents
• api
• config
• core
• knowledge
• logging
• services
• tools
• utils
• web (Frontend)
• docs (Documentation)
• scripts
• tests
• Other: ...

Checklist

• I have read and followed the contribution guidelines.
• My code follows the project's coding standards.
• I have run pre-commit run --all-files and fixed any issues.
• I have added relevant tests for my changes.
• I have updated the documentation (if necessary).
• My changes do not introduce any new security vulnerabilities.

Additional Notes

Add any other context or screenshots about the pull request here.

[arsaboo]

@pancacake thanks for those upstream fixes...all green now :)