feat(cli): hint that Copilot usage records no per-message tokens (#349)

[mjacobs]

GitHub Copilot bills via a monthly premium-request quota rather than per-token, so its session files frequently record no per-message token usage. usage daily --agent copilot then shows all-zeros / $0.00 with no explanation, which reads as "spent nothing" (#349).

This adds a one-line stderr note from usage daily when the agent filter is an all-Copilot filter and the totals are zero. The agent filter accepts comma-separated lists, so IsCopilotAgentFilter treats an all-Copilot list (e.g. copilot,vscode-copilot) as Copilot. The note is an agent-property statement shown in response to an explicit --agent the user typed, so it needs no session-presence check.

Scope: this is the CLI half of #349. The dashboard hint is the harder half — to avoid showing it for an empty view it needs a timezone-correct, filter-faithful matching-session count from the sessions table (to distinguish "Copilot sessions with no usage" from "no matching sessions"), which is a cross-backend change worth its own PR. Tracked separately; this PR is intentionally scoped to the CLI.

Where to look

• cmd/agentsview/usage.go (noTokenDataNote).
• internal/db/usage.go (NoTokenData, IsCopilotAgentFilter).

[roborev-ci]

roborev: Combined Review (c2a4480)

Summary verdict: One medium issue should be fixed before merge; no security findings were reported.

Medium

• internal/service/usage.go:188: MatchingSessions is computed by translating UsageFilter to SessionFilter, but the filters are not equivalent. The mapping drops ExcludeAgent and model filters, and SessionFilter treats Project/ExcludeProject as single exact values even though usage filters support comma-separated values. This can make matchingSessions positive when the actual usage filter matches no sessions, causing the Copilot no-token-data hint to appear for an empty view.

  Fix: Count matching sessions with a query that reuses the usage filter predicates and CSV semantics, or extend SessionFilter and this mapping to preserve all relevant usage filters. Add tests for exclude_agent and multi-project exclusions.

---

Panel: ci_default_security | Synthesis: codex, 6s | Members: codex_default (codex/default, done, 6m9s), codex_security (codex/security, done, 46s) | Total: 7m1s

[roborev-ci]

roborev: Combined Review (5ad8c5e)

No issues found.

---

Panel: ci_default_security | Synthesis: codex | Members: codex_default (codex/default, done, 4m24s), codex_security (codex/security, done, 27s) | Total: 4m51s