Update docs for Java 25 and GKE migration (#3089)

Summarize all documentation updates across the repository to align with modern GKE, Cloud SQL Proxy v2, standard EPP fee v1.0, and Postgres database environments.

Key Updates:
- Prerequisites: Bump Java requirement to Java 25.
- Architecture & Scaling: Document GKE workloads, Cloud Tasks queues, and scheduled tasks. Replace App Engine references with GKE deployment restart commands (kubectl rollout restart).
- Configuration: Update Cloud SQL Proxy instructions to v2, fix keyring verification commands, and document IAP configuration.
- Escrow (RDE/BRDA): Fix manual generation and download procedures to match the Dataflow job ID folder structure, and correct deposit encryption/verification command parameters.
- Monitoring: Correct metric names and expand the documented metrics list with caching, locking, and reserved list metrics.
- Fixes: Standardize lists formatting across markdown files, fix broken webdriver links, and resolve various typos.
- Cleanup: Remove leftover cloud scheduler configurations for the deleted wipeOutContactHistoryPii task, and update ICANN reporting documentation to reflect open-sourced DNS query coordinator.

TAG=agy
CONV=88271e71-e272-40e0-85f8-a075a423b7c2

docs/code-structure.md

@@ -20,12 +20,13 @@ versions stored in the various `gradle.lockfile` files. To update these
 versions, run any Gradle command (e.g. `./gradlew build`) with the
 `--write-locks` argument.
 
-### Generating WAR archives for deployment
+### Generating Docker images for deployment
 
-The `jetty` project is the main entry point for building the Nomulus WAR files,
-and one can use the `war` gradle task to build the base WAR file. The various
-deployment/release files use Docker to deploy this, in a system that is too
-Google-specialized to replicate directly here.
+The `jetty` project is the main entry point for building the Nomulus Docker
+images. You can use the `./gradlew :jetty:buildNomulusImage` task to build the
+image locally, which contains the compiled WAR files and Angular assets staged
+inside a Jetty base image. You can use `./gradlew :jetty:pushNomulusImage` to
+push this image to your GCR/Artifact Registry repository.
 
 ## Subprojects
 
@@ -68,6 +69,12 @@ The following cursor types are defined:
     events into one-time `BillingEvent`s.
 *   **`SYNC_REGISTRAR_SHEET`** - Tracks the last time the registrar spreadsheet
     was successfully synced.
+*   **`ICANN_UPLOAD_TX`** - Tracks monthly uploads of ICANN transaction reports.
+*   **`ICANN_UPLOAD_ACTIVITY`** - Tracks monthly uploads of ICANN activity reports.
+*   **`REMOTE_CACHE_DOMAIN_SYNC`** - Tracks the reflection of domain changes in
+    the remote cache.
+*   **`REMOTE_CACHE_HOST_SYNC`** - Tracks the reflection of host changes in
+    the remote cache.
 
 All `Cursor` entities in the database contain a `DateTime` that represents the
 next timestamp at which an operation should resume processing and a `CursorType`