feat(models): add support for local Ollama models (#39)

[tsdevau]

• Added dual provider support with a new diffCommit.provider configuration option
• Implemented Ollama integration with model selection and server configuration
• Added new commands for Ollama setup and model switching:
  • DiffCommit: Configure Ollama Model
  • DiffCommit: Change Ollama Model
• Added new configuration settings:
  • diffCommit.ollamaHostname for server connection
  • diffCommit.ollamaModel for model selection
• Updated documentation with Ollama requirements and setup instructions
• Enhanced error handling for Ollama-specific scenarios
• Updated workflow documentation to include provider selection

Resolves issue #37

[Copilot]

Pull Request Overview

This PR extends Diff Commit with support for local Ollama models as an alternative to Anthropic, introducing new configuration options, commands, and documentation updates.

• Added diffCommit.provider, ollamaHostname, and ollamaModel settings with corresponding defaults
• Implemented OllamaManager and updated CommitMessageGenerator to branch on provider
• Registered new commands (Configure Ollama Model, Change Ollama Model) and updated tests and docs

Reviewed Changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/configManager.ts	Added provider and Ollama-related fields with defaults
src/ollamaManager.ts	New manager for selecting and changing Ollama host/models
src/commitMessageGenerator.ts	Extended generator with Ollama branch, prompt builder, and error handling
src/extension.ts	Branched commit command on provider and registered new commands
package.json	Updated description, dependencies, and configuration schema
README.md	Documented Ollama usage, commands, and new config properties

Comments suppressed due to low confidence (2)

src/commitMessageGenerator.ts:151

• The parameter name 'isIdiotOllamaModel' is unprofessional and unclear. Rename it to something like 'useOllamaFormat' or 'isOllamaProvider' to improve readability and maintainability.

isIdiotOllamaModel: boolean = false,

src/commitMessageGenerator.ts:98

• There are no unit tests verifying the successful path of 'generateOllamaMessage'. Add tests to ensure that a valid Ollama response produces the expected commit message output.

private async generateOllamaMessage(diff: string, config: CommitConfig): Promise<string | undefined> {

[tsdevau]

Re-merging PR with corrected title and minor code fixes.