docs: add gateway-target documents five of eight target types, connector and web search are missing

[sundargthb]

Description

agentcore add gateway-target accepts eight --type values at main (31e98b7), but the docs describe five. The three
missing from the docs are connector, http-runtime and passthrough. connector is the only way to add a managed web
search or Bedrock Knowledge Bases target, so web search reads as unsupported to anyone working from docs/.

The help string in the code lists all eight (src/cli/primitives/GatewayTargetPrimitive.ts:278):

Target type (required): mcp-server, api-gateway, open-api-schema, smithy-model, lambda-function-arn, http-runtime, connector, passthrough [non-interactive]

Three pages are affected:

• docs/commands.md, add gateway-target: says "Supports five target types" and the --type row lists five.
  --connector, --knowledge-base-id and --exclude-domains are not documented anywhere on the page, although
  --connector <id> is registered at GatewayTargetPrimitive.ts:299 and --exclude-domains <list> at :309.
• docs/configuration.md:493: the targetType field is documented as mcpServer, lambda, openApiSchema,
  smithyModel, apiGateway or lambdaFunctionArn. The schema also validates connector, httpRuntime and
  passthrough (src/schema/schemas/mcp.ts:746, :637, :681), and a connector target carries a connectorId and a
  configurations[] array that the page does not describe.
• docs/gateway.md: README.md:228 sends readers here "for full target setup", and the strings connector and
  web-search appear zero times in it.

README.md:218 does document the web search target, so the README and docs/ disagree with each other.

Steps to Reproduce

1. Read the add gateway-target section of docs/commands.md.
2. Run agentcore add gateway-target --help.
3. Compare the --type values in each.

Expected Behavior

The documented target types match the ones the CLI accepts, and --connector, --knowledge-base-id and
--exclude-domains appear in the add gateway-target flag table with an example for web search and one for Bedrock
Knowledge Bases.

Actual Behavior

docs/commands.md documents five of the eight types and none of the connector flags. docs/configuration.md documents
six of the nine targetType values. docs/gateway.md does not mention connector targets at all.

CLI Version

0.28.1

Operating System

macOS

Additional Context

Verified by reading the repository at main (31e98b7).

Web search itself is not gated. src/cli/feature-flags.ts checks ENABLE_GATED_FEATURES, and the only target type
still behind it is passthrough (e2e-tests/httpgateway-all-targets.test.ts:74). The connector path is covered by
e2e-tests/web-search-lifecycle.test.ts and integ-tests/add-remove-web-search.test.ts.

Web search did move in and out of a gate earlier this year (#1558, reverted in #1567, #1597, re-gated in #1625, tests
restored in #1711), which may be how the docs were left behind.