docs(telemetry): fold tier guide into the runbook

Remove the standalone docker/telemetry/DEPLOYMENT_TIERS.md; its content now
lives in the "Deployment Tiers" section of docs/telemetry-runbook.md, the
established operator doc. Repoint the Grafana Cloud collector config comment
at that section.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker/telemetry/DEPLOYMENT_TIERS.md

@@ -1,94 +0,0 @@
-# Deployment tiers — filtering telemetry by environment, network, and node
-
-Multiple xrpld instances can send telemetry to per-tier collectors that all
-forward to one Grafana stack. Four resource attributes segregate the data so
-one dashboard set serves every deployment:
-
-| Dimension   | Attribute                | Set by     | Example values                 |
-| ----------- | ------------------------ | ---------- | ------------------------------ |
-| Node        | `service.instance.id`    | xrpld cfg  | `alice-laptop`, `ci-runner-7`  |
-| Service     | `service.name`           | xrpld cfg  | `xrpld`, `pratik-xrpld`        |
-| Network     | `xrpl.network.type`      | xrpld node | `mainnet`, `testnet`, `devnet` |
-| Environment | `deployment.environment` | collector  | `local`, `test`, `ci`, `prod`  |
-
-The dashboards expose these as the template variables `$node`,
-`$service_name`, `$xrpl_network_type`, and `$deployment_environment`
-(each variable name matches its Prometheus label).
-
-## Who owns which attribute
-
-- **Node and service** come from the xrpld config (`[insight]` /
-  `[telemetry]` `service_instance_id` and `service_name`). They are unique
-  per process.
-- **Network** is a property of the chain the node joined. The node derives
-  it from `[network_id]` and stamps `xrpl.network.type` on all three signals.
-- **Environment** is a property of where the collector runs. Each collector
-  serves one environment and stamps it.
-
-## The upsert vs insert rule
-
-The collector's `resource/tier` processor uses two different actions on
-purpose:
-
-- `deployment.environment` → **`upsert`** (overwrite). The collector _is_ the
-  environment, so it is authoritative.
-- `xrpl.network.type` → **`insert`** (fill only if absent). The node already
-  knows its real network, so the collector must not overwrite it. `insert`
-  only supplies a value when the source did not — e.g. an older xrpld build
-  whose metrics predate node-side network stamping. This is what makes a
-  local node connected to mainnet report `network=mainnet`, not the
-  collector's default.
-
-## Configuring a collector for a tier
-
-Each tier runs its own collector. Edit the `resource/tier` processor in the
-collector config (`otel-collector-config.yaml` for local backends, or
-`otel-collector-config.grafanacloud.yaml` for Grafana Cloud export) and set
-the two values for that tier:
-
-```yaml
-processors:
-  resource/tier:
-    attributes:
-      - key: deployment.environment
-        value: <tier> # local | test | ci | prod
-        action: upsert
-      - key: xrpl.network.type
-        value: <network> # mainnet | testnet | devnet (fallback only)
-        action: insert
-```
-
-Suggested values per tier:
-
-| Collector           | `deployment.environment` | `xrpl.network.type` (fallback) |
-| ------------------- | ------------------------ | ------------------------------ |
-| Developer laptop    | `local`                  | `devnet`                       |
-| Test machines       | `test`                   | `testnet`                      |
-| CI runs             | `ci`                     | `testnet`                      |
-| Production observer | `prod`                   | `mainnet`                      |
-
-The `xrpl.network.type` value is only a fallback: when the xrpld node stamps
-its own network (all current builds do), the node's value wins. Set it to the
-network the collector most commonly serves so older or misconfigured sources
-still land under a sensible label.
-
-## How the labels reach metrics
-
-Resource attributes do not become Prometheus labels automatically. Two config
-settings make it work, both already enabled:
-
-- `prometheus.resource_to_telemetry_conversion: enabled: true` promotes
-  resource attributes to metric labels on the local scrape surface.
-- `spanmetrics.resource_metrics_key_attributes` lists the tier attributes so
-  span-derived metric series stay grouped per node and tier.
-
-Traces and logs carry resource attributes natively, so no extra setting is
-needed for them. Grafana Cloud ingests all three signals' attributes over
-OTLP directly.
-
-## Filtering in Grafana
-
-Pick the dashboard template variables top-down: `$deployment_environment` →
-`$xrpl_network_type` → `$service_name` → `$node`. Selecting **All** on any
-variable matches every value, including series that lack the label, so mixed
-old/new data never disappears.