[SideNav] v1 Component Clean-Up

[Dosant]

Summary

• First pass - just component and the related code in chrome

Next steps:

• Nav tree structure
• Functional tests helpers

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)

[tsullivan]

Some README files can still be updated:

diff --git src/core/packages/chrome/browser-internal/src/project_navigation/README.md src/core/packages/chrome/browser-internal/src/project_navigation/README.md
index a400f8055a6..5ae983f706a 100644
--- src/core/packages/chrome/browser-internal/src/project_navigation/README.md
+++ src/core/packages/chrome/browser-internal/src/project_navigation/README.md
@@ -34,20 +34,8 @@ The following diagram illustrates how navigation state flows through the system
                                         |                 |
                                         +--------+--------+
                                                  |
-                                                 | NavigationKibanaProvider
-                                                 | adapts streams
-                                                 v
-                                        +------------------+
-                                        | NavigationProvider|
-                                        |                  |
-                                        |  +-----------+   |
-                                        |  | Context   |   |
-                                        |  +-----------+   |
-                                        |                  |
-                                        +--------+--------+
-                                                 |
-                                                 | useNavigation() hook
-                                                 | consumes context
+                                                 | Props passed directly
+                                                 | via useObservable()
                                                  v
                                         +------------------+
                                         | Navigation       |
@@ -56,8 +44,8 @@ The following diagram illustrates how navigation state flows through the system
                                         | - Renders UI     |
                                         | - Highlights     |
                                         |   active items   |
-                                        | - Shows          |
-                                        |   breadcrumbs    |
+                                        | - Manages panel  |
+                                        |   state          |
                                         +------------------+
 ```
 
@@ -78,8 +66,8 @@ The service does not contain any UI. Instead, it processes navigation trees regi
 
 This is the most common function of the service. It determines the currently active link and broadcasts it to the UI.
 
--   **State Stream**: The active state is exposed as an RxJS observable, `activeNodes$`, which streams the active link and its parent breadcrumbs.
--   **UI Consumption**: The `ChromeService` subscribes to this stream using the `useObservable` hook and passes the static result to the React UI as a prop.
+-   **State Stream**: The active state is exposed as an RxJS observable, `activeNodes$`, which streams the active link and its parent nodes.
+-   **UI Consumption**: The `ChromeService` subscribes to this stream using the `useObservable` hook and passes the result directly to the Navigation component as props.
 -   **Detection Algorithm**: The active node is found by the `findActiveNodes` utility, which uses two methods:
     1.  **Custom Logic (`getIsActive`)**: A node can define its own function for complex activation logic.
     2.  **Longest URL Match**: As a fallback, the utility finds the most specific link by matching the longest URL prefix.
@@ -95,9 +83,9 @@ Breadcrumbs are automatically generated from the navigation tree structure:
 
 #### Active Item Highlighting
 
-UI components use the `activeNodes$` observable to highlight the currently active navigation item:
+The Navigation component uses the active nodes information to highlight the currently active navigation item:
 
-1. The `SideNavComponent` subscribes to `activeNodes$` to determine which items to highlight
+1. The Navigation component receives `activeNodes$` data via props
 2. When rendering the navigation tree, each item compares its ID with the active node's ID
 3. If they match, the item is rendered with an "active" state (different styling)
 4. Parent nodes of the active item may also receive special styling to show the active path
diff --git src/core/packages/chrome/layout/core-chrome-layout-feature-flags/README.md src/core/packages/chrome/layout/core-chrome-layout-feature-flags/README.md
index 70eb206b5a1..3530e9663dd 100644
--- src/core/packages/chrome/layout/core-chrome-layout-feature-flags/README.md
+++ src/core/packages/chrome/layout/core-chrome-layout-feature-flags/README.md
@@ -8,19 +8,16 @@ Feature flag utilities for Kibana's Chrome layout system.
 import {
   getLayoutVersion,
   getLayoutDebugFlag,
-  getSideNavVersion,
 } from '@kbn/core-chrome-layout-feature-flags';
 
 const layoutType = getLayoutVersion(featureFlags); // 'legacy-fixed' | 'grid'
 const isDebug = getLayoutDebugFlag(featureFlags); // boolean
-const sideNavVersion = getSideNavVersion(featureFlags); // 'v1' | 'v2' | 'both'
 ```
 
 ## Feature Flags
 
 - **`LAYOUT_FEATURE_FLAG_KEY`**: Layout type selection
 - **`LAYOUT_DEBUG_FEATURE_FLAG_KEY`**: Debug mode toggle
-- **`LAYOUT_PROJECT_SIDENAV_FEATURE_FLAG_KEY`**: Side navigation version
 
 ## Functions

And, src/platform/test/functional/page_objects/solution_navigation.ts can probably be substantially updated.

[Dosant]

thanks @tsullivan,

I updated the readmes!

This is the first pass, I will follow with the NavigationTree types clean up and functional tests utils clean up. These changes will touch solutions code and I didn't want to trigger them in this pr

[tsullivan]

LGTM! Thanks for updating the read me files :)

[elasticmachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 4365c8e
• Storybooks Preview

Failed CI Steps

• FTR Configs #16
• FTR Configs #75
• FTR Configs #103

Test Failures

• [job] [logs] FTR Configs #103 / Ingest pipelines app Ingest Pipelines Pipelines list Pipelines tree Clicking on tree nodes open details panel for selected pipeline
• [job] [logs] FTR Configs #75 / Observability Rules Rules Endpoints Metric threshold rule > alert and action creation "after all" hook for "should set correct action parameter: ruleType"

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
core	557	528	-29
navigation	47	14	-33
total			-62

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
@kbn/core-chrome-browser	101	100	-1
@kbn/core-chrome-layout-feature-flags	11	7	-4
@kbn/shared-ux-chrome-navigation	40	-	-40
total			-45

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
core	130.7KB	107.7KB	-23.0KB

Public APIs missing exports

Total count of every type that is part of your API that should be exported but is not. This will cause broken links in the API documentation system. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats exports for more detailed information.

id	before	after	diff
@kbn/core	913	909	-4
@kbn/shared-ux-chrome-navigation	1	-	-1
total			-5

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
core	511.0KB	508.2KB	-2.8KB
navigation	10.7KB	9.7KB	-1.0KB
total			-3.8KB

Unknown metric groups

API count

id	before	after	diff
@kbn/core-chrome-browser	208	207	-1
@kbn/core-chrome-layout-feature-flags	11	7	-4
@kbn/shared-ux-chrome-navigation	49	-	-49
total			-54

async chunk count

id	before	after	diff
core	4	3	-1

ESLint disabled line counts

id	before	after	diff
@kbn/core-chrome-browser-internal	7	6	-1
@kbn/shared-ux-chrome-navigation	2	-	-2
total			-3

Total ESLint disabled count

id	before	after	diff
@kbn/core-chrome-browser-internal	7	6	-1
@kbn/shared-ux-chrome-navigation	2	-	-2
total			-3

History

• 💛 Build #356930 was flaky 1b3fdbf
• 💚 Build #356755 succeeded 36f75a6
• 💚 Build #356629 succeeded 05adea9
• 💚 Build #356348 succeeded 37ae291
• 💔 Build #356178 failed 38eacb4
• 💔 Build #356162 failed d90ce45