Bug: [DOCS]: Add `X-Merchant-Id` to headers in Profile endpoints for v2 



### Description

We require `X-Merchant-Id` in the headers for the following endpoints in Profile:

- Profile - Create
- Profile - Update
- Profile - Retrieve
- Merchant Connector - List

We need to update the v2 API documentation.
diff --git a/api-reference-v2/openapi_spec.json b/api-reference-v2/openapi_spec.json
index 3f57faaf1d7..46c4868e4bd 100644
--- a/api-reference-v2/openapi_spec.json
+++ b/api-reference-v2/openapi_spec.json
@@ -711,6 +711,20 @@
         "summary": "Profile - Create",
         "description": "Creates a new *profile* for a merchant",
         "operationId": "Create A Profile",
+        "parameters": [
+          {
+            "name": "X-Merchant-Id",
+            "in": "header",
+            "description": "Merchant ID of the profile.",
+            "required": true,
+            "schema": {
+              "type": "string"
+            },
+            "example": {
+              "X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"
+            }
+          }
+        ],
         "requestBody": {
           "content": {
             "application/json": {
@@ -767,6 +781,18 @@
             "schema": {
               "type": "string"
             }
+          },
+          {
+            "name": "X-Merchant-Id",
+            "in": "header",
+            "description": "Merchant ID of the profile.",
+            "required": true,
+            "schema": {
+              "type": "string"
+            },
+            "example": {
+              "X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"
+            }
           }
         ],
         "responses": {
@@ -806,6 +832,18 @@
             "schema": {
               "type": "string"
             }
+          },
+          {
+            "name": "X-Merchant-Id",
+            "in": "header",
+            "description": "Merchant ID of the profile.",
+            "required": true,
+            "schema": {
+              "type": "string"
+            },
+            "example": {
+              "X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"
+            }
           }
         ],
         "requestBody": {
@@ -864,6 +902,18 @@
             "schema": {
               "type": "string"
             }
+          },
+          {
+            "name": "X-Merchant-Id",
+            "in": "header",
+            "description": "Merchant ID of the profile.",
+            "required": true,
+            "schema": {
+              "type": "string"
+            },
+            "example": {
+              "X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"
+            }
           }
         ],
         "responses": {
diff --git a/crates/openapi/src/routes/profile.rs b/crates/openapi/src/routes/profile.rs
index f726c76db84..fc56e642719 100644
--- a/crates/openapi/src/routes/profile.rs
+++ b/crates/openapi/src/routes/profile.rs
@@ -139,6 +139,13 @@ pub async fn profile_list() {}
 #[utoipa::path(
     post,
     path = "/v2/profiles",
+    params(
+        (
+            "X-Merchant-Id" = String, Header,
+            description = "Merchant ID of the profile.",
+            example = json!({"X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"})
+        ),
+    ),
     request_body(
         content = ProfileCreate,
         examples(
@@ -169,7 +176,12 @@ pub async fn profile_create() {}
     put,
     path = "/v2/profiles/{profile_id}",
     params(
-        ("profile_id" = String, Path, description = "The unique identifier for the profile")
+        ("profile_id" = String, Path, description = "The unique identifier for the profile"),
+        (
+            "X-Merchant-Id" = String, Header,
+            description = "Merchant ID of the profile.",
+            example = json!({"X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"})
+        ),
     ),
     request_body(
         content = ProfileCreate,
@@ -276,7 +288,12 @@ pub async fn routing_update_default_config() {}
     get,
     path = "/v2/profiles/{profile_id}",
     params(
-        ("profile_id" = String, Path, description = "The unique identifier for the profile")
+        ("profile_id" = String, Path, description = "The unique identifier for the profile"),
+        (
+            "X-Merchant-Id" = String, Header,
+            description = "Merchant ID of the profile.",
+            example = json!({"X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"})
+        ),
     ),
     responses(
         (status = 200, description = "Profile Updated", body = ProfileResponse),
@@ -339,6 +356,11 @@ pub async fn routing_retrieve_default_config() {}
     path = "/v2/profiles/{profile_id}/connector_accounts",
     params(
         ("profile_id" = String, Path, description = "The unique identifier for the business profile"),
+        (
+            "X-Merchant-Id" = String, Header,
+            description = "Merchant ID of the profile.",
+            example = json!({"X-Merchant-Id": "abc_iG5VNjsN9xuCg7Xx0uWh"})
+        ),
     ),
     responses(
         (status = 200, description = "Merchant Connector list retrieved successfully", body = Vec<MerchantConnectorResponse>),

## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [x] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
Add X-Merchant-Id to headers in Profile endpoints for v2

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

<!--
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2. `crates/router/src/configs`
3. `loadtest/config`
-->


## Motivation and Context
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If it fixes an open issue, please link to the issue here.

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## How did you test it?
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## Checklist
<!-- Put an `x` in the boxes that apply -->

- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [ ] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible
