Unified reports ignore source-specific config sections #1957

What happened?

Unified reports (ccusage, ccusage daily, weekly, monthly, session) load every source with the same shared options and never read <source>.defaults, <source>.commands.<report> or commands.<source>:<report>. The config docs say the opposite:

• docs/guide/config-files.md:290: "Source-specific settings are also applied when running unified reports such as ccusage daily. In that case, each source receives its own merged options before data is loaded."
• docs/guide/configuration.md:145 says the same.

This is a regression from the TypeScript CLI (up to v19.0.3): apps/ccusage/src/commands/all.ts built one merged option set per agent (mergeAllOptions, merging the config under the name <agent> <kind>) and loaded each agent with it. The native Rust CLI (#977) hands one SharedArgs to every loader.

Where it goes wrong on main (e42e1b4):

• rust/crates/ccusage-config/src/config.rs:92: option_maps reads <agent>.* only when the detected command has an agent, and ccusage daily has none.
• rust/crates/ccusage-adapter-all/src/loader.rs:117: load_base_rows builds one loader_shared and hands it to all 18 loaders.
• rust/crates/ccusage-adapter-all/src/loader.rs:685 and :698 hardcode CodexSpeed::Auto; :219 loads pi with custom_path: None; :246 loads OpenClaw with None. So codex.defaults.speed, pi.defaults.piPath and openclaw.defaults.openClawPath have no effect on unified reports either, even though the same keys drive ccusage codex daily, ccusage pi daily and ccusage openclaw daily.

Steps to reproduce

1. Keep pi sessions outside the default directory, for example /data/pi/sessions.

2. Write .ccusage/ccusage.json:

   {
     "pi": { "defaults": { "piPath": "/data/pi/sessions" } },
     "codex": { "defaults": { "speed": "fast", "since": "20260101" } }
   }

3. Compare ccusage pi daily with ccusage daily: the focused report shows the pi usage, the unified report does not (pi is missing from the Detected: line).

4. Compare ccusage codex daily with ccusage daily: the unified report prices Codex at the auto-detected tier instead of Fast, and ignores the since bound, so the Codex totals differ between the two reports.

Expected behavior

A unified report loads each source with the options ccusage <source> <report> would use: defaults, then commands.<report>, then <source>.defaults, then <source>.commands.<report>, with command-line flags still on top, as the docs describe.

I would like to implement this. Proposed approach: resolve one option set per source in the binary by parsing the same command line against that source's view of the config (so flags keep their precedence over config), carry those per-source options on AgentCommandArgs, and have the unified loader use them per source, including the Codex speed and the pi and OpenClaw paths.

Version

20.0.42 (main at e42e1b4)