Add AI context item usage data and page

I'll leave the code review for someone more on the BE-side, but on the UX/frontend side everything is looking good to me. Seems like a real nice addition to the module and everything is clear on how to use it.

Emma and reviewed and #34 looks good. We're assuming the main use case we're using these logs for is:

"why does my page suck"... Hmm is it the context or the agent prompt or what...?

Table Update suggestions:

1. Agent should link to the Agent config page
2. Entity should be a link to the rendered page / entity.
3. Add a view link to view single log record.

Create a "entity view" for each log item record. (Similar to looking at a single Drupal watchdog log)

1. Move Route info from the table into single log item view
2. Print the actual Prompt / Context info here (so I can see if something unexpected was attached)
3. Maybe a history of calls, not the full logs but if it ran 50 times on a single call I would like know if it's running
4. Token usage

Taking a look at this one.

Updated MR !35:
https://git.drupalcode.org/project/ai_context/-/merge_requests/35

This adds the remaining UX items discussed in the thread (agent/entity links + single record view).

Changes
- Usage view: Agent column links to the agent config form.
- Usage view: Entity column links to the target entity (when available).
- Usage view: Added a "View" link column to open a single usage record page (watchdog-style).
- Single record page (/admin/ai/context/usage/): shows Tools used, Routes, and renders the current Context item content.
- Moved Routes out of the table into the single record page (kept the Route filter exposed).
- Merged latest from 1.0.x.
- Update hook: updates the ai_context_usage View display config on existing sites.
- Update hook: installs the new ai_context_item created field storage on existing sites (prevents missing column errors).
- Composer: ensure dynamic_entity_reference is required (module still uses this field type).
- Config schema: added scheduler third_party_settings schema for ai_context_item_type.
- Added a Kernel test for the usage tracker service.
- Docs: clarified AI Agent setup steps in README (create agents at /admin/config/ai/agents).

Quick verification
- Visit /admin/ai/context/usage and confirm Agent/Entity link behavior and the new "View" link column.
- Click "View" for a record and confirm the single record page renders Tools used, Routes, and Context item content.

Testing (local DDEV)
- PHPCS (Drupal, DrupalPractice): PASS
- PHP lint (changed files): PASS
- PHPUnit (ai_context module tests): PASS (49 deprecations on Drupal 11.3.x)
- drush updb / cr: PASS
- drupal-intent-testing compare run: IDENTICAL (0 JS errors, 0 Drupal alerts); screenshots attached

Related
- Installation error "The state 'draft' already exists in workflow" is tracked in https://www.drupal.org/project/ai_context/issues/3571188 (MR !51). Tested: enabling ai_context fails without MR !51 and succeeds with it on a fresh Drupal 11 install. This MR intentionally does not include that fix.

AI disclosure
This work was AI-assisted (analysis/drafting), with human review + local testing.

I can do a review of this one.

When visiting admin/ai/context/usage, I'm getting a database error of the missing ai_context_usage table...

Drupal\Core\Database\DatabaseExceptionWrapper: Exception in AI Context Usage[ai_context_usage]: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'db.ai_context_usage' doesn't exist: SELECT COUNT(*) AS "expression" FROM (SELECT 1 AS "expression" FROM "ai_context_usage" "ai_context_usage") "subquery"; Array ( ) in main() (line 19 of index.php).

This is after I ran the database updates...

1. Install ai_context@1.x-dev
2. Switch to the MR!35 branch
3. Run database updates ddev drush updatedb
4. Cleared the caches ddev drush cr
5. Visit admin/ai/context/usage: ddev launch admin/ai/context/usage

Need the schema definition?

Updated MR !35:

Addressed the upgrade regression where visiting /admin/ai/context/usage failed with a missing ai_context_usage table after running updates.

Changes in this update

• Added ai_context_update_8004() in ai_context.install to install ai_context_usage entity schema on existing sites when missing.
• This is separate from the install-time workflow bug in #3571188 / MR !51; that fix remains tracked there.

Reproduction and verification

• Reproduced the issue on a fresh Drupal 11 site:
• Install drupal/ai_context:dev-1.0.x
• Switch module code to MR !35 branch
• Run drush updb -y and drush cr
• Querying ai_context_usage failed with SQLSTATE[42S02] (table missing)
• Applied this update-hook fix and reran the same flow:
• drush updb -y ran ai_context_update_8004
• SHOW TABLES LIKE 'ai_context_usage' returned the table
• Entity query on ai_context_usage succeeded (count returned 0)
• Testing (local DDEV)

• ddev exec php -l web/modules/contrib/ai_context/ai_context.install : PASS
• ddev exec vendor/bin/phpcs -s --standard=Drupal,DrupalPractice web/modules/contrib/ai_context/ai_context.install : PASS
• ddev exec drush updb -y : PASS
• ddev exec drush cr : PASS
• ddev exec bash -lc 'SIMPLETEST_DB=mysql://db:db@db/db SIMPLETEST_BASE_URL=https://canvas-dev.ddev.site:8443 BROWSERTEST_OUTPUT_DIRECTORY=/var/www/html/web/sites/simpletest/browser_output vendor/bin/phpunit -c web/core/phpunit.xml.dist web/modules/contrib/ai_context/tests' : PASS (49 deprecations on Drupal 11.3.x)

AI disclosure
This work was AI-assisted (analysis/drafting), with human review + local testing.