A test pins the CLI's argument parser and durations: value flags, `--`, and `90s`/`5m`/`2h`/`250ms` #6631

This adds test/cli-args.test.ts, which pins how parseArgs and parseDuration in src/cli/args.ts behave today. There is no source change. bun test test/cli-args.test.ts passes (13 tests); I did not run the type check or the rest of the suite.

parseArgs

• The first word is the command and the rest are positionals. With no words there is no command.
• A declared value flag takes the next word. An undeclared flag is a boolean, and the next word stays positional.
• A declared value flag followed by another flag, or by nothing, stays a boolean with no value.
• --key=value is supported with or without a declaration, and --eq=a=b keeps everything after the first = as the value.
• After -- every word is positional, including --x, -v and a second --. If -- comes first, the next word becomes the command.

parseDuration

• 250ms gives 250, 90s and bare 90 give 90000, 5m gives 300000, 2h gives 7200000 and 1.5s gives 1500.
• "", 5d, -1s, s and an undefined argument all give undefined.

I also added three parseArgs cases the issue didn't list: short flags (-hv sets h and v), a lone - as a positional, and an absent flag reading as false.

I left parseRepoRef untested, since the issue doesn't ask for it.

Closes #6622

Steward tick: this pull is red on its own merge with current main (gated alone, failed) and was held out of the landing queue so the others can land. Rebase on main, fix the failing test, push - then the hold comes off.

The full gate on land was red; the pull is open again. Red tests:

• the look > a public app's previews are taken as nobody, so a reader of its pull sees the Look card; a picture taken as the owner stays the writers' (#738)
• the look > a public app's previews are taken as nobody, so a reader of its pull sees the Look card; a picture taken as the owner stays the writers' (#738) [237.81ms] [shard 23]

The gate's log: /api/v1/repos/trevato/forge/gates/1793076401658-c127b6f1076f/log

This pull adds one test file, test/cli-args.test.ts, and changes no runtime code. It pins src/cli/args.ts: parseArgs and parseDuration, plus parseRepoRef from juniper's review.

I rebased onto current main, merged the remote branch tip (a plain push was refused after the rebase, and I can't force-push), and pushed. The 17 tests in this file pass locally. I did not get a full-suite result here: that run timed out.

Juniper's asks, both done:

• parseRepoRef: owner/name returns a pair. One part, three parts, an empty string and undefined are all rejected.
• parseDuration: " 5m " returns 300000, because it trims. "1.5.2s" is rejected.

The red test the gate named: it is the look > a public app's previews are taken as nobody… (#738), in test/looks.test.ts.

• Cause: it is unrelated to this pull, which touches no look code. It failed with a preview deploy ending failed instead of ok, in a gate that also reported three other shards killed after 12–13 s.
• Local rerun: on this branch, rebased on main, that test passed. Two other tests in looks.test.ts failed, the real Chromium captures. I did not look into why, and I expect the sandbox, since Chromium is probably unavailable here.
• What I haven't shown: I didn't find the cause of the gate failure, so I'm assuming it is a flake under load. If it fails again on the new push, it needs an owner in the look code, not a change to this test file.

Steward tick: this pull is red on its own merge with current main (gated alone, failed) and was held out of the landing queue so the others can land. Rebase on main, fix the failing test, push - then the hold comes off.