Introduce "agents"

An agent is currently a name given to a system prompt and a set of
tools which the agent has access to.

This resolves the previous issue of the set of configured tools being
available in *all* contexts, which wasn't always desired. Tools are now
only available when an agent is explicitly requested using the
`-a/--agent` flag.

Agents are expected to be expanded on: the concept of task-specilized
agents (e.g. coding), the ability to define a set of files an agent
should always have access to for RAG purposes, etc.

Other changes:

- Removes the "tools" top-level config structure (though this is expected
to come back along with the abillity to define custom tools).

- Renamed `pkg/agent` to `pkg/agents`

pkg/lmcli/config.go

@@ -15,6 +15,8 @@ type Config struct {
 		Temperature      *float32 `yaml:"temperature" default:"0.2"`
 		SystemPrompt     string   `yaml:"systemPrompt,omitempty"`
 		SystemPromptFile string   `yaml:"systemPromptFile,omitempty"`
+		// CLI only
+		Agent string `yaml:"-"`
 	} `yaml:"defaults"`
 	Conversations *struct {
 		TitleGenerationModel *string `yaml:"titleGenerationModel" default:"gpt-3.5-turbo"`
@@ -23,9 +25,11 @@ type Config struct {
 		Style     *string `yaml:"style" default:"onedark"`
 		Formatter *string `yaml:"formatter" default:"terminal16m"`
 	} `yaml:"chroma"`
-	Tools *struct {
-		EnabledTools []string `yaml:"enabledTools"`
-	} `yaml:"tools"`
+	Agents []*struct {
+		Name         string   `yaml:"name"`
+		SystemPrompt string   `yaml:"systemPrompt"`
+		Tools        []string `yaml:"tools"`
+	} `yaml:"agents"`
 	Providers []*struct {
 		Name    string   `yaml:"name,omitempty"`
 		Kind    string   `yaml:"kind"`

pkg/lmcli/lmcli.go

@@ -6,7 +6,7 @@ import (
 	"path/filepath"
 	"strings"
 
-	"git.mlow.ca/mlow/lmcli/pkg/agent"
+	"git.mlow.ca/mlow/lmcli/pkg/agents"
 	"git.mlow.ca/mlow/lmcli/pkg/api"
 	"git.mlow.ca/mlow/lmcli/pkg/api/provider/anthropic"
 	"git.mlow.ca/mlow/lmcli/pkg/api/provider/google"
@@ -18,20 +18,24 @@ import (
 	"gorm.io/gorm"
 )
 
+type Agent struct {
+	Name         string
+	SystemPrompt string
+	Toolbox      []api.ToolSpec
+}
+
 type Context struct {
 	// high level app configuration, may be mutated at runtime
 	Config Config
 	Store  ConversationStore
-
-	Chroma       *tty.ChromaHighlighter
-	EnabledTools []api.ToolSpec
+	Chroma *tty.ChromaHighlighter
 }
 
 func NewContext() (*Context, error) {
 	configFile := filepath.Join(configDir(), "config.yaml")
 	config, err := NewConfig(configFile)
 	if err != nil {
-		Fatal("%v\n", err)
+		return nil, err
 	}
 
 	databaseFile := filepath.Join(dataDir(), "conversations.db")
@@ -43,20 +47,12 @@ func NewContext() (*Context, error) {
 	}
 	store, err := NewSQLStore(db)
 	if err != nil {
-		Fatal("%v\n", err)
+		return nil, err
 	}
 
 	chroma := tty.NewChromaHighlighter("markdown", *config.Chroma.Formatter, *config.Chroma.Style)
 
-	var enabledTools []api.ToolSpec
-	for _, toolName := range config.Tools.EnabledTools {
-		tool, ok := agent.AvailableTools[toolName]
-		if ok {
-			enabledTools = append(enabledTools, tool)
-		}
-	}
-
-	return &Context{*config, store, chroma, enabledTools}, nil
+	return &Context{*config, store, chroma}, nil
 }
 
 func (c *Context) GetModels() (models []string) {
@@ -82,6 +78,40 @@ func (c *Context) GetModels() (models []string) {
 	return
 }
 
+func (c *Context) GetAgents() (agents []string) {
+	for _, p := range c.Config.Agents {
+		agents = append(agents, p.Name)
+	}
+	return
+}
+
+func (c *Context) GetAgent(name string) *Agent {
+	if name == "" {
+		return nil
+	}
+
+	for _, a := range c.Config.Agents {
+		if name != a.Name {
+			continue
+		}
+
+		var enabledTools []api.ToolSpec
+		for _, toolName := range a.Tools {
+			tool, ok := agents.AvailableTools[toolName]
+			if ok {
+				enabledTools = append(enabledTools, tool)
+			}
+		}
+
+		return &Agent{
+			Name:         a.Name,
+			SystemPrompt: a.SystemPrompt,
+			Toolbox:      enabledTools,
+		}
+	}
+	return nil
+}
+
 func (c *Context) DefaultSystemPrompt() string {
 	if c.Config.Defaults.SystemPromptFile != "" {
 		content, err := util.ReadFileContents(c.Config.Defaults.SystemPromptFile)