refactor: Rename recommender to sizer

CLAUDE.md

@@ -28,7 +28,7 @@ make install-hooks            # Install pre-commit and commit-msg hooks
 
 ## Architecture Overview
 
-This is a Go metrics collector designed for CI/CD environments with shared PID namespaces. It consists of two binaries:
+A resource optimiser for CI/CD environments with shared PID namespaces. It consists of two binaries — a **collector** and a **receiver** (which includes the **sizer**):
 
 ### Collector (`cmd/collector`)
 Runs alongside CI workloads, periodically reads `/proc` filesystem, and pushes a summary to the receiver on shutdown (SIGINT/SIGTERM).
@@ -40,11 +40,12 @@ Runs alongside CI workloads, periodically reads `/proc` filesystem, and pushes a
 4. On shutdown, `summary.PushClient` sends the summary to the receiver HTTP endpoint
 
 ### Receiver (`cmd/receiver`)
-HTTP service that stores metric summaries in SQLite (via GORM) and provides a query API.
+HTTP service that stores metric summaries in SQLite (via GORM), provides a query API, and includes the **sizer** — which computes right-sized Kubernetes resource requests and limits from historical data.
 
 **Key Endpoints:**
 - `POST /api/v1/metrics` - Receive metrics from collectors
 - `GET /api/v1/metrics/repo/{org}/{repo}/{workflow}/{job}` - Query stored metrics
+- `GET /api/v1/sizing/repo/{org}/{repo}/{workflow}/{job}` - Compute container sizes from historical data
 
 ### Internal Packages
 
@@ -55,7 +56,7 @@ HTTP service that stores metric summaries in SQLite (via GORM) and provides a qu
 | `internal/proc` | Low-level /proc parsing (stat, status, cgroup) |
 | `internal/cgroup` | Parses CGROUP_LIMITS and CGROUP_PROCESS_MAP env vars |
 | `internal/summary` | Accumulates samples, computes stats, pushes to receiver |
-| `internal/receiver` | HTTP handlers and SQLite store |
+| `internal/receiver` | HTTP handlers, SQLite store, and sizer logic |
 | `internal/output` | Metrics output formatting (JSON/text) |
 
 ### Container Metrics

README.md

@@ -1,10 +1,10 @@
-# Forgejo Runner Resource Collector
+# Forgejo Runner Optimiser
 
-A lightweight metrics collector for CI/CD workloads in shared PID namespace environments. Reads `/proc` to collect CPU and memory metrics, groups them by container/cgroup, and pushes run summaries to a receiver service for storage and querying.
+A resource optimiser for CI/CD workloads in shared PID namespace environments. The **collector** reads `/proc` to gather CPU and memory metrics grouped by container/cgroup, and pushes run summaries to the **receiver**. The receiver stores metrics and exposes a **sizer** API that computes right-sized Kubernetes resource requests and limits from historical data.
 
 ## Architecture
 
-The system has two independent binaries:
+The system has two binaries — a **collector** and a **receiver** (which includes the sizer):
 
 ```
 ┌─────────────────────────────────────────────┐       ┌──────────────────────────┐
@@ -19,7 +19,9 @@ The system has two independent binaries:
 │  └───────────┘  └────────┘  └───────────┘   │       │         │                │
 │                                             │       │         ▼                │
 └─────────────────────────────────────────────┘       │  GET /api/v1/metrics/... │
-                                                      └──────────────────────────┘
+│  GET /api/v1/sizing/...  │
+│       (sizer)            │
+└──────────────────────────┘
 ```
 
 ### Collector
@@ -56,9 +58,9 @@ Runs as a sidecar alongside CI workloads. On a configurable interval, it reads `
 
 CPU supports Kubernetes notation (`"2"` = 2 cores, `"500m"` = 0.5 cores). Memory supports `Ki`, `Mi`, `Gi`, `Ti` (binary) or `K`, `M`, `G`, `T` (decimal).
 
-### Receiver
+### Receiver (with sizer)
 
-HTTP service that stores metric summaries in SQLite (via GORM) and exposes a query API.
+HTTP service that stores metric summaries in SQLite (via GORM), exposes a query API, and provides a **sizer** endpoint that computes right-sized Kubernetes resource requests and limits from historical run data.
 
 ```bash
 ./receiver --addr=:8080 --db=metrics.db --read-token=my-secret-token --hmac-key=my-hmac-key
@@ -78,6 +80,7 @@ HTTP service that stores metric summaries in SQLite (via GORM) and exposes a que
 - `POST /api/v1/metrics` — receive and store a metric summary (requires scoped push token)
 - `POST /api/v1/token` — generate a scoped push token (requires read token auth)
 - `GET /api/v1/metrics/repo/{org}/{repo}/{workflow}/{job}` — query stored metrics (requires read token auth)
+- `GET /api/v1/sizing/repo/{org}/{repo}/{workflow}/{job}` — compute container sizes from historical data (requires read token auth)
 
 **Authentication:**
 
@@ -232,7 +235,7 @@ PUSH_TOKEN=$(curl -s -X POST http://localhost:8080/api/v1/token \
 | `internal/cgroup`    | Parses `CGROUP_PROCESS_MAP` and `CGROUP_LIMITS` env vars            |
 | `internal/collector` | Orchestrates the collection loop and shutdown                       |
 | `internal/summary`   | Accumulates samples, computes stats, pushes to receiver             |
-| `internal/receiver`  | HTTP handlers and SQLite store                                      |
+| `internal/receiver`  | HTTP handlers, SQLite store, and sizer logic                        |
 | `internal/output`    | Metrics output formatting (JSON/text)                               |
 
 ## Background

internal/receiver/sizing.go

@@ -1,5 +1,5 @@
 // ABOUTME: Computes ideal container sizes from historical run data.
-// ABOUTME: Provides Kubernetes-style resource recommendations.
+// ABOUTME: Provides Kubernetes-style resource sizes.
 package receiver
 
 import (