feat: simplify AI chat architecture and add record links (#16463)

## Summary

This PR significantly simplifies the AI chat architecture by removing
complex routing/planning mechanisms and introduces clickable record
links in AI responses.

## Changes

### AI Chat Architecture Simplification
- **Removed** the entire `ai-chat-router` module (~850 lines) including:
  - Strategy decider service
  - Plan generator service
  - Complex routing logic
- **Removed** agent execution planning services (~700 lines):
  - `agent-execution.service.ts`
  - `agent-plan-executor.service.ts`
  - `agent-tool-generator.service.ts`
- **Added** centralized `ToolRegistryService` for tool management:
  - Builds searchable tool index (database, action, workflow tools)
  - Provides tool lookup by name
  - Supports agent search for loading expertise
- **Added** `ChatExecutionService` as simple replacement:
  - Includes full tool catalog in system prompt
- Pre-loads common tools (find/create/update for company, person,
opportunity, task, note)
  - Uses `load_tools` mechanism for dynamic tool activation
  - Enables native web search by default

### Record References in AI Responses
- Added `recordReferences` field to tool outputs for create, find, and
update operations
- Implemented `[[record:objectName:recordId:displayName]]` syntax for AI
to reference records
- Created `RecordLink` component that renders clickable chips with
object icons
- Integrated record link parsing into the markdown renderer
- Users can now click directly on created/found records in AI responses

### Workflow Agent Fixes
- Fixed cache invalidation issue when creating agents in workflows
- Added default prompt for workflow-created agents to prevent validation
errors
- Relaxed agent validation to only check properties being updated (not
all required properties)

### Code Quality Improvements
- Extracted `getRecordDisplayName` utility that mirrors frontend's
`getLabelIdentifierFieldValue` logic
- Uses object metadata to determine the correct label identifier field
- Handles `FULL_NAME` composite type for person/workspaceMember objects
- Shared across create, find, and update record services

## Net Impact
- **~1,200 lines deleted** (complex routing/planning code)
- **~500 lines added** (simpler tool registry + record links)
- Significantly reduced code complexity
- Better tool discovery through full catalog in system prompt
- Improved UX with clickable record references

## Testing
- Typecheck passes
- Lint passes
- Manual testing of AI chat with record creation and linking

packages/twenty-server/src/engine/workspace-manager/workspace-migration-v2/workspace-migration-builder-v2/validators/services/flat-agent-validator.service.ts

@@ -168,6 +168,7 @@ export class FlatAgentValidatorService {
     validationResult.errors.push(
       ...validateAgentRequiredProperties({
         flatAgent: optimisticFlatAgent,
+        updatedProperties: partialFlatAgent,
       }),
     );
 

packages/twenty-server/src/engine/workspace-manager/workspace-migration-v2/workspace-migration-builder-v2/validators/utils/validate-agent-required-properties.util.ts

@@ -1,18 +1,28 @@
-import { isNonEmptyString } from '@sniptt/guards';
 import { msg, t } from '@lingui/core/macro';
+import { isNonEmptyString } from '@sniptt/guards';
 
 import { AgentExceptionCode } from 'src/engine/metadata-modules/ai/ai-agent/agent.exception';
 import { type FlatAgent } from 'src/engine/metadata-modules/flat-agent/types/flat-agent.type';
 import { type FlatEntityValidationError } from 'src/engine/workspace-manager/workspace-migration-v2/workspace-migration-builder-v2/builders/types/failed-flat-entity-validation.type';
 
+type ValidateAgentRequiredPropertiesArgs = {
+  flatAgent: FlatAgent;
+  updatedProperties?: Partial<FlatAgent>;
+};
+
 export const validateAgentRequiredProperties = ({
   flatAgent,
-}: {
-  flatAgent: FlatAgent;
-}): FlatEntityValidationError<AgentExceptionCode>[] => {
+  updatedProperties,
+}: ValidateAgentRequiredPropertiesArgs): FlatEntityValidationError<AgentExceptionCode>[] => {
   const errors: FlatEntityValidationError<AgentExceptionCode>[] = [];
 
-  if (!isNonEmptyString(flatAgent.label)) {
+  // For updates, only validate properties that are being changed
+  const isUpdate = updatedProperties !== undefined;
+  const shouldValidateLabel = !isUpdate || 'label' in updatedProperties;
+  const shouldValidatePrompt = !isUpdate || 'prompt' in updatedProperties;
+  const shouldValidateModelId = !isUpdate || 'modelId' in updatedProperties;
+
+  if (shouldValidateLabel && !isNonEmptyString(flatAgent.label)) {
     errors.push({
       code: AgentExceptionCode.INVALID_AGENT_INPUT,
       message: t`Label cannot be empty`,
@@ -20,7 +30,7 @@ export const validateAgentRequiredProperties = ({
     });
   }
 
-  if (!isNonEmptyString(flatAgent.prompt)) {
+  if (shouldValidatePrompt && !isNonEmptyString(flatAgent.prompt)) {
     errors.push({
       code: AgentExceptionCode.INVALID_AGENT_INPUT,
       message: t`Prompt cannot be empty`,
@@ -28,7 +38,7 @@ export const validateAgentRequiredProperties = ({
     });
   }
 
-  if (!isNonEmptyString(flatAgent.modelId)) {
+  if (shouldValidateModelId && !isNonEmptyString(flatAgent.modelId)) {
     errors.push({
       code: AgentExceptionCode.INVALID_AGENT_INPUT,
       message: t`Model ID cannot be empty`,