quota: z.ai credit-bucket back-pressure + resource gate + usage accounting (Redmine 490+491)

The loop now consults quota and host state before every dispatch and
DEFERS gated work with a logged reason instead of letting turns die at
the provider (the 2026-08-28 19:00 quota-wall failure mode, replayed as
a test). Adds internal/quota: 5h/weekly credit buckets (provider poll
when z.ai ships an endpoint - fake-server tested - else locally
estimated from the documented credit formula), TZ-aware peak window
(default 01:00-05:00 America/Chicago weekdays, matching the documented
z.ai peak Mon-Fri 14:00-18:00 Singapore), block/defer thresholds, a
read-only load/mem/disk/IO-PSI monitor, an optional redis shared-state
hop (stdlib RESP2 mini-client) so all instances of an account
coordinate, per-class token+credit accounting in loop.jsonl, and
`harness quota status|probe|gate`. Config: [quota] + [resources]
sections; README runbook covers the redis container and deploy-time
cgroup enforcement.

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

internal/loop/loop.go

@@ -17,6 +17,7 @@ import (
 	"ukrrs.com/mopac/harness/internal/intake"
 	"ukrrs.com/mopac/harness/internal/llm"
 	"ukrrs.com/mopac/harness/internal/models"
+	"ukrrs.com/mopac/harness/internal/quota"
 	"ukrrs.com/mopac/harness/internal/task"
 	"ukrrs.com/mopac/harness/internal/tools"
 	"ukrrs.com/mopac/harness/internal/writeback"
@@ -35,6 +36,9 @@ type Conductor struct {
 	bash   *tools.BashTool
 	keys   *config.KeyResolver
 	out    io.Writer
+	gate   *quota.Gate
+	// deferLogged dedups defer log lines per (task, updated_on, reason).
+	deferLogged map[string]bool
 }
 
 // New validates routing config and prepares the tool palette.
@@ -57,9 +61,17 @@ func New(cfg *config.Config, out io.Writer) (*Conductor, error) {
 			return nil, err
 		}
 	}
-	return &Conductor{cfg: cfg, router: router, bash: bash, keys: config.NewKeyResolver(cfg), out: out}, nil
+	keys := config.NewKeyResolver(cfg)
+	gate, err := buildGates(cfg, keys)
+	if err != nil {
+		return nil, err
+	}
+	return &Conductor{cfg: cfg, router: router, bash: bash, keys: keys, out: out, gate: gate, deferLogged: map[string]bool{}}, nil
 }
 
+// Gate exposes the quota gate (nil when off) for `harness quota status`.
+func (c *Conductor) Gate() *quota.Gate { return c.gate }
+
 // OnceOpts controls a single iteration.
 type OnceOpts struct {
 	DryRun bool   // intake + plan only, no LLM call