internal/cli: subcommand dispatch, flags, exit codes

[Saber5656]

Title

internal/cli: subcommand dispatch, flags, exit codes

Summary

Implement the CLI shell from DESIGN.md §4: subcommand routing for
daily|standup|init|doctor|sources|version, per-subcommand flag.FlagSets
with the documented flags, usage/help text, config loading + validation
wiring, and the exit-code contract — with each subcommand body still a stub.

Context

Issues 25–29 fill in the subcommand bodies; this issue gives them a uniform
harness (parsed flags + loaded config + resolved report date handed to a
run function) so wiring stays consistent and testable. version becomes
fully functional here.

Scope

• internal/cli/cli.go (dispatch, shared flag struct, usage),
  version.go (complete), daily.go, standup.go, init.go, doctor.go,
  sources.go (stubs returning "not implemented" errors), tests.
• Rewrite cmd/worklog/main.go to call cli.Main(os.Args[1:], os.Stdout, os.Stderr) int and exit with its return value.

Detailed Requirements

1. cli.Main contract: pure function of args + writers (no os.Exit
   inside; returns the exit code) so tests can drive it end-to-end.
2. Flags exactly per DESIGN §4:
   • shared: --config, --date, --lang, --verbose
     (on daily|standup|doctor|sources);
   • daily|standup only: --out, --save, --force, --no-llm,
     --redact (values on|off only), --source (comma list, each value
     must be one of the four source ids AND present in sources.enabled;
     violations = usage error);
   • init only: --config, --force.
3. Behavior in this issue:
   • worklog with no args, -h, --help, help → usage to stderr
     listing subcommands + one-line descriptions; exit 2 for no-args/unknown,
     0 for explicit help.
   • Unknown subcommand → unknown subcommand "x" + usage, exit 2.
   • Flag parse error → FlagSet error + subcommand usage, exit 2.
   • For daily|standup|doctor|sources: load config (config.Load), print
     unknown-key warnings to stderr as warning: unknown config key: <key>,
     run Validate() — any error → all errors to stderr, exit 2. Then parse
     --date (via timeutil, in the configured timezone) — invalid → exit 2.
     Then call the stub, which returns an error → message to stderr, exit 1.
     (Stub exit-1 is a TEMPORARY scaffolding exception to the DESIGN §13
     exit-code contract, removed as issues 25/26/28/29 replace the stubs;
     mark each stub with a // TODO(issue NN) comment.)
   • version: prints worklog <Version> (<Commit>) (from
     internal/version, values "dev"/"none" when unset) to stdout, exit 0.
4. --lang overrides general.language; --redact overrides
   redaction.mode; --no-llm overrides llm.enabled; overrides are
   applied to the in-memory config copy handed to subcommands.
5. Diagnostics discipline (DESIGN §4): stubs and all harness messages write
   only to stderr; stdout is reserved for reports/version output.
6. --verbose stores a flag on the context struct passed to subcommands
   (used later); no logging framework.

Acceptance Criteria

• Exit-code matrix test via cli.Main: no args→2, --help→0, unknown
  subcommand→2, daily --date bad→2, daily (stub)→1, version→0,
  daily --redact maybe→2, daily --source nope→2, daily --save
  without configured output directory→2 (checked here in the harness,
  per DESIGN §13).
• version prints exactly one line to stdout; nothing to stderr.
• Config warnings/errors surface as specified (fixture config with typo
  key + one invalid value; assert stderr contents and exit code).
• Stubs write nothing to stdout.
• gofmt/vet/lint green; no new dependencies.

Validation

go test -race -cover ./internal/cli/ plus a manual transcript in the PR:
worklog, worklog help, worklog version, worklog daily,
worklog daily --date 2026-07-10 against an empty HOME (expected stub
error, exit 1).

Dependencies

01, 05 (config), 04 (date parsing).

Non-goals

Real subcommand behavior (25–29), output writing (22), doctor checks (28).

Design References

• docs/DESIGN.md §4, §13

---

Source of truth: docs/issues/07-cli-skeleton.md (PR #1, branch docs/v1-design). If this issue and the repo docs disagree, the docs win. Execution order and dependencies: docs/ISSUE_PLAN.md (this is issue 07 of 33).