[Bug]: DAB configuration properties not available via MCP

### Description

The following properties have no corresponding MCP change type. They cannot be viewed or modified through the tool. Paths reference the [v2.0.1-rc schema](https://github.com/Azure/data-api-builder/releases/download/v2.0.1-rc/dab.draft.schema.json).

#### Data source
- `data-source.connection-string`
- `data-source.database-type` (mssql, postgresql, mysql, cosmosdb_nosql, dwsql)
- `data-source.options` (e.g. `set-session-context` for mssql, `database`/`container`/`schema` for cosmosdb_nosql)
- `data-source.health.enabled` / `.name` / `.threshold-ms`
- `data-source.user-delegated-auth.enabled` / `.provider` / `.database-audience`
- `data-source-files` (multi-database configuration)

#### Runtime host
- `runtime.host.mode` (production, development)
- `runtime.host.max-response-size-mb`
- `runtime.host.cors.origins` / `.allow-credentials`
- `runtime.host.authentication.provider` (StaticWebApps, EntraID, AzureAD, AppService, Simulator, Custom, Unauthenticated)
- `runtime.host.authentication.jwt.audience` / `.issuer`

#### REST (global)
- `runtime.rest.path`
- `runtime.rest.request-body-strict`

#### GraphQL (global)
- `runtime.graphql.path`
- `runtime.graphql.allow-introspection`
- `runtime.graphql.depth-limit`
- `runtime.graphql.multiple-mutations.create.enabled`

#### MCP (global)
- `runtime.mcp.path`
- `runtime.mcp.description`
- `runtime.mcp.dml-tools` (describe-entities, create-record, read-records, update-record, delete-record, execute-entity, aggregate-records)

#### Cache
- `runtime.cache.enabled` / `.ttl-seconds`
- `runtime.cache.level-2.enabled` / `.provider` / `.connection-string` / `.partition`
- `entities..cache.enabled` / `.ttl-seconds` / `.level`

#### Pagination
- `runtime.pagination.default-page-size` / `.max-page-size`
- `runtime.pagination.next-link-relative`

#### Compression
- `runtime.compression.level` (optimal, fastest, none)

#### Telemetry
- `runtime.telemetry.application-insights.connection-string` / `.enabled`
- `runtime.telemetry.open-telemetry.endpoint` / `.headers` / `.service-name` / `.exporter-protocol` / `.enabled`
- `runtime.telemetry.azure-log-analytics.enabled` / `.auth` / `.dab-identifier` / `.flush-interval-seconds`
- `runtime.telemetry.file.enabled` / `.path` / `.rolling-interval` / `.retained-file-count-limit` / `.file-size-limit-bytes`
- `runtime.telemetry.log-level`

#### Health
- `runtime.health.enabled` / `.roles` / `.cache-ttl-seconds` / `.max-query-parallelism`
- `entities..health.enabled` / `.first` / `.threshold-ms`

#### Entity source
- `entities..source.type` (table, view, stored-procedure)
- `entities..source.object`
- `entities..source.parameters` (stored procedure parameter mappings)
- `entities..source.key-fields` (deprecated; replaced by `fields[].primary-key`)
- `entities..source.description`
- Views (not discovered; cannot be added manually)
- Stored procedures (not discovered; cannot be added manually)

#### Entity fields & mapping
- `entities..fields[]` (name, alias, description, primary-key)
- `entities..mappings` (deprecated; replaced by `fields[].alias`)
- `entities..description`

#### Entity permissions
- Custom role definitions (only `anonymous` and `authenticated` are available)
- `entities..permissions[].role` / `.actions[]`
- `entities..permissions[].actions[].fields.include` / `.exclude`
- `entities..permissions[].actions[].policy.database` (item-level security)

#### Entity relationships
- `entities..relationships..cardinality` (one, many)
- `entities..relationships..target.entity`
- `entities..relationships..source.fields` / `.target.fields`
- `entities..relationships..linking.object` / `.linking.source.fields` / `.linking.target.fields`

#### Entity-level REST & GraphQL
- `entities..rest.enabled` / `.path` / `.methods`
- `entities..graphql.enabled` / `.type` (singular/plural) / `.operation`

#### Entity-level MCP
- `entities..mcp.dml-tools`
- `entities..mcp.custom-tool`

#### Azure Key Vault
- `azure-key-vault.endpoint`
- `azure-key-vault.retry-policy.*`

#### Auto-entities
- `autoentities..patterns` (include, exclude, name)
- `autoentities..template` (mcp, rest, graphql, health, cache)
- `autoentities..permissions`

#### Lifecycle
- Add a new entity from an existing table/view/SP
- Remove an entity from the configuration
- Export / save configuration to a `dab-config.json` file
- Start / stop the DAB runtime

### Steps to Reproduce

Use Copilot against MCP.

### Affected Area

- [ ] Connection dialog (SQL Server | Azure browse/Fabric browse)
- [ ] Query editor
- [ ] Query results panel
- [ ] Object Explorer
- [ ] GitHub Copilot integration
- [ ] Preview/Edit data
- [ ] Table Designer
- [x] Schema Designer
- [ ] Schema Compare
- [ ] Local SQL Server Container provisioning
- [ ] SQL database in Fabric provisioning
- [ ] DACPAC/BACPAC export/import
- [ ] SQL Database projects
- [ ] Query Plan Visualizer
- [ ] Other (please describe below)

### If you selected "Other", please describe the affected area

_No response_

### Environment Information

Identifier: ms-mssql.mssql
Version: 1.42.2
OS: Windows
DB: Local SQL

### Confirmation

- [x] I have searched existing issues and couldn't find a match
- [ ] I want to work on this issue