Make document ID optional with auto-generation of human-readable IDs

[Copilot]

Overview

This PR implements the requested feature to make document IDs optional in the API. When no ID is provided, the system now auto-generates human-readable, short IDs that are easy to read and understand.

Changes Made

Core Functionality

• Added GenerateDocumentID() function that creates human-readable IDs with the format: adjective-noun-YYMMDD-HHMM
• Modified JSON API endpoint (POST /api/index) to auto-generate ID when missing from request body
• Modified file upload endpoint to auto-generate ID when missing from form data
• Updated API documentation in the static HTML page to reflect that IDs are now optional

API Examples

Before (required ID):

POST /api/index
{"id": "my-document", "text": "Content here"}

After (ID optional):

POST /api/index
{"text": "Content here"}
// Returns: {"success": true, "id": "clever-note-250902-1530", "message": "..."}

File upload also works without ID:

curl -X POST -F "file=@document.txt" http://localhost:8080/api/index
// Auto-generates ID like "bright-doc-250902-1530"

Generated ID Characteristics

• Human-readable: Uses friendly adjectives and nouns (e.g., "smart-paper-250902-1530")
• Short: Typically under 25 characters
• Unique: Combines timestamp precision with randomness
• URL-safe: Only lowercase letters, numbers, and hyphens
• Predictable format: Always follows adjective-noun-YYMMDD-HHMM pattern

Backward Compatibility

✅ Fully backward compatible - existing code that provides IDs continues to work exactly as before. Only new behavior is that missing IDs are auto-generated instead of returning an error.

Testing

• Added comprehensive tests for ID generation including format validation, uniqueness checks, and character restrictions
• Updated existing tests to expect success when ID is omitted instead of validation errors
• All existing tests continue to pass, ensuring no regressions

Example Generated IDs

clever-content-250902-1530
bright-sheet-250902-1531  
bold-record-250902-1532
quick-note-250902-1533

This change significantly improves the developer experience by removing the burden of having to generate unique IDs while still allowing full control when specific IDs are desired.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[Copilot]

Pull Request Overview

This PR implements optional document IDs with auto-generation of human-readable IDs for the document indexing API. When no ID is provided, the system generates readable IDs following the pattern adjective-noun-YYMMDD-HHMM.

• Auto-generates human-readable document IDs when not provided in API requests
• Updates both JSON and file upload endpoints to handle missing IDs gracefully
• Maintains full backward compatibility with existing code that provides explicit IDs

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
pkg/minirag/chunker.go	Adds GenerateDocumentID() function for creating human-readable IDs
pkg/minirag/chunker_test.go	Comprehensive tests for ID generation including format validation and uniqueness
internal/handlers/handlers.go	Updates API endpoints to auto-generate IDs when missing and updates documentation
internal/handlers/handlers_test.go	Updates tests to expect success for missing IDs and adds Ollama connection handling

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

Using UnixNano() as a seed for random number generation creates predictable sequences when calls happen within the same nanosecond. Consider using crypto/rand for better randomness or implement additional entropy sources.

[Copilot]

The adjectives list is duplicated between the test and production code. Consider extracting this to a shared constant or variable to avoid maintenance issues when the word lists are updated.

Suggested change

	adjectives := []string{
	"happy", "bright", "swift", "clever", "gentle", "bold", "calm", "wise",
	"brave", "quick", "sharp", "smart", "clean", "fresh", "light", "clear",
	}
	adjectives := Adjectives

[Copilot]

The Ollama connection error handling logic is duplicated in multiple test cases. Consider extracting this into a helper function to reduce code duplication and improve maintainability.