[Doc] Adjust the file structure under concepts

[misi1987107]

Purpose of this pull request

related #10262
adjust the doc structure

Does this PR introduce any user-facing change?

How was this patch tested?

Check list

• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs
• If necessary, please update incompatible-changes.md to describe the incompatibility caused by this PR.
• If you are contributing the connector code, please check that the following files are updated:
  1. Update plugin-mapping.properties and add new connector information in it
  2. Update the pom file of seatunnel-dist
  3. Add ci label in label-scope-conf
  4. Add e2e testcase in seatunnel-e2e
  5. Update connector plugin_config

[davidzollo]

[DanielCarter-stack]

Issue 1: incompatible-changes.md missing from sidebar navigation

Location: docs/sidebars.js:45 (exists in dev branch, deleted in HEAD)

Related context:

• File location: docs/en/introduction/concepts/incompatible-changes.md
• Original sidebar configuration: "introduction/concepts/incompatible-changes"
• Sidebar configuration change: Deleted in commit ec0188d17

Problem description:
The incompatible-changes.md file documents breaking changes between SeaTunnel versions and is must-read documentation for users before upgrading. Although the file itself still exists, its navigation reference was deleted in sidebars.js, preventing users from finding this document through the documentation website's sidebar.

Document content:
This document contains the following key information:

• API Changes: Engine REST API table-level metric key format changes (affects Grafana, Prometheus integration)
• Transform Changes:
  • DataValidator table_id format changes
  • SQL Transform datetime function behavior changes

Potential risks:

• Risk 1: Users are unaware of breaking changes when upgrading versions, which may cause production environment failures
• Risk 2: Monitoring dashboards and alert rules that depend on old metric keys become invalid, but users don't know they need to update them
• Risk 3: SQL query result changes (datetime function behavior changes), leading to data errors

Impact scope:

• Direct impact: All users upgrading SeaTunnel versions
• Indirect impact:
  • Grafana dashboard configurations need to be updated
  • Prometheus alert rules need to be modified
  • Jobs using DataValidator and SQL Transform may be affected
• Impact surface: Core documentation/all upgrading users

Severity: CRITICAL

Improvement suggestions:

// docs/sidebars.js - should be kept in Introduction > Concepts category
{
    "type": "category",
    "label": "Concepts",
    "items": [
        "introduction/concepts/config",
        "introduction/concepts/connector-v2-features",
        "introduction/concepts/schema-feature",
        "introduction/concepts/incompatible-changes"  // Must keep
    ]
}

Rationale:

• This document is mandatory reading before upgrading and should be placed in a prominent position
• Even if the documentation structure is adjusted, the navigation entry for this document should not be removed
• Recommend keeping it under Concepts, or moving it to the top level of Introduction

---

Issue 2: Lack of documentation structure change description and migration guide

Location: PR description, docs/en/introduction/about.md

Problem description:
This PR reorganizes the documentation structure, but provides no change description, so users don't know:

• Which documents have been moved
• How to handle old links
• How to find the moved documents

Potential risks:

• Risk 1: Users' bookmarks become invalid and they cannot find the new location
• Risk 2: Links in external tutorials and blogs become invalid
• Risk 3: Search engine indexes become invalid, affecting documentation discoverability

Impact scope:

• Direct impact: All users viewing documentation
• Indirect impact: Third-party content referencing SeaTunnel documentation
• Impact surface: Overall documentation usability

Severity: MAJOR

Improvement suggestions:

1. Add change description in docs/en/introduction/about.md:

## Document Structure Updates

### January 2026
The documentation structure has been reorganized for better clarity:
- Configuration-related docs moved to `introduction/configuration/`
- Connector-specific docs moved to `connectors/`
- Engine-specific docs moved to `engines/`

If you're looking for a document that was previously in `introduction/concepts/`, please check:
- [Configuration](../introduction/configuration/)
- [Connectors](../connectors/)
- [Engines](../engines/)

2. Create redirect pages for old paths (if deployment supports):

---
redirect: ../configuration/JobEnvConfig
---

3. Add change checklist in PR description:

### Document Structure Changes
- Moved `introduction/concepts/JobEnvConfig.md` → `introduction/configuration/JobEnvConfig.md`
- Moved `introduction/concepts/connector-isolated-dependency.md` → `connectors/connector-isolated-dependency.md`
- Moved `introduction/concepts/event-listener.md` → `engines/event-listener.md`
- ... (完整列表)

Rationale:

• Improve user experience and reduce confusion
• Lower migration costs
• Demonstrate respect for users

---

Issue 3: External link compatibility issues

Location: All moved documents

Problem description:
After documents are moved, all external links pointing to old paths will become invalid, including:

• Internal cross-references in official documentation (although updated, there may be omissions)
• Third-party tutorials, blogs
• User bookmarks
• Search engine indexes

Potential risks:

• Risk 1: Users get 404 errors when accessing through old links
• Risk 2: Reduced documentation accessibility and user satisfaction
• Risk 3: Affects SeaTunnel's professional image

Impact scope:

• Direct impact: All users accessing documentation through links
• Indirect impact: Third-party content referencing documentation
• Impact surface: Documentation ecosystem

Severity: MAJOR

Improvement suggestions:

1. Configure HTTP redirect rules (in documentation deployment configuration):

# For example in docusaurus.config.js or Web server configuration
redirects:
  - from: /docs/en/introduction/concepts/JobEnvConfig
    to: /docs/en/introduction/configuration/JobEnvConfig
  - from: /docs/en/introduction/concepts/connector-isolated-dependency
    to: /docs/en/connectors/connector-isolated-dependency
  # ... all other moved documents

2. Create redirect documents (if server redirects cannot be configured):

---
title: JobEnvConfig
---
# Document Moved

This document has been moved to [JobEnvConfig](../introduction/configuration/JobEnvConfig.md).

Please update your bookmarks.

Rationale:

• Ensure backward compatibility
• Improve user experience
• Align with Web best practices

---

Issue 4: Insufficient PR description information

Location: PR description

Problem description:
The PR description is too simple and does not provide:

• Specific change checklist
• Explanation of change reasons
• Explanation of relationship with PR [DOC]Optimize Seatunnel Document Structure #10262
• Key points for review

Potential risks:

• Risk 1: Reviewers find it difficult to understand the complete scope of the PR
• Risk 2: Difficult to trace change history after merging
• Risk 3: Other contributors cannot understand the evolution of documentation structure

Impact scope:

• Direct impact: PR review process
• Indirect impact: Project maintenance and knowledge transfer
• Impact surface: Collaboration efficiency

Severity: MINOR

Improvement suggestions:

### Purpose of this pull request

This is a follow-up to PR #10262 to further optimize the document structure.

### Changes Made

1. **Created new `configuration` directory** under `introduction/`
   - Moved 7 configuration-related docs from `concepts/` to `configuration/`
   - Updated internal cross-references

2. **Reorganized topic-specific docs**
   - `connector-isolated-dependency.md` → `connectors/`
   - `event-listener.md` → `engines/`

3. **Updated navigation**
   - Added `Configuration` category in sidebar
   - Simplified `Concepts` category
   - Moved docs to appropriate categories

### File Movement List

See the diff for complete list of moved files.

### Related PRs
- #10262: Initial document structure optimization
- #10351: Previous doc structure adjustment

### Breaking Changes
- External links to moved docs will break (need redirects)
- Users' bookmarks may need updating

Rationale:

• Improve review efficiency
• Facilitate tracing change history
• Demonstrate professionalism

---

[davidzollo]

+1
LGTM

[zhangshenghang]

+1