the-daily-epub/docs/plans/briefs/web-dashboard/05-settings.md

Step 5 — Settings

Read 00-shared.md, the plan (§3, §4.2 "Config reload", §13 in full, §15, §16, §17 "Settings schema" and "Settings writer"), src/config.rs in full (every struct, validate, load, resolve_path, check_report, ENV_PREFIX, ENV_SPLIT, the DAILY_EPUB_SECRET alias, the stale-key checks), the README configuration table and config.example.toml, and the handoffs for steps 1–4. This is plan §19 item 5.

Deliverables

1. src/web/dashboard/settings.rs: schema(config, file) -> Vec<SettingGroup> derived by walking toml::Value::try_from(Config::default()) and the current config in parallel (§13.1) — one SettingField per leaf with path, group, kind, current, default, source (Default/File/Env(name)), help, restart_required. Kinds and the static enum table exactly as §13.1 item 3; SETTINGS_HELP seeded from the README table and config.example.toml comments, one entry per shipped key (test). Groups render in the §13.1 item 5 order; each group gets an id anchor equal to its dotted path (step 4 links to these).
2. GET /dashboard/settings (§4.2 reload-on-mtime first; report a file that fails to load with the ! banner and keep the previous config live), dashboard/settings.html: Secret fields as set/not set, Env fields disabled with the lock note, everything else as an input with the default beside it and a reset affordance; weights note. POST /dashboard/settings implements §13.2 exactly: toml_edit::DocumentMut, only changed fields written ("explicit beats implicit"), typed by kind, TextList as a multi-line array with trailing comma, field errors collected before any write, render → <path>.tmp.<pid> → validate with Config::load(Some(tmp)) → copy permissions → rename → swap state.config; one config_changes row per changed key; flash with the restart note for restart_required keys; config_path == None → 400.
3. Providers (§13.3): remove (refused when an [llm] role names it) and add ([a-z0-9_]+, must not exist, ProviderConfig::default() with the chosen kind and placeholders) through the same validate-and-rename path, with config_changes rows.
4. GET /dashboard/settings/history (§13.4), dashboard/settings_history.html.
5. systemd/daily-epub.service: add /etc/daily-epub to ReadWritePaths (the SupplementaryGroups line is step 6).
6. Tests (§17): every leaf of Config::default() appears exactly once; every shipped key has help; secrets are Secret with no value; env detection uses the derived name (set the env var inside the test with a unique key and restore it); enum options round-trip through validate(); starting from config.example.toml changing three keys preserves every comment and the order of untouched lines; a new key in an absent table creates the table; TextList multi-line; an invalid value (e.g. deep_keep < shortlist_keep) is rejected and the file untouched; permissions preserved; config_changes rows; provider add/remove; removing a referenced provider refused; reload on mtime swaps the config.