Bring the docs landing page back in line with CLI.html

[carpentry-agent]

docs/index.html is the hand-kept landing page for carpentry.dev/cli. gendocs.carp sets (Project.config "docs-generate-index" false), so save-docs never writes it, and it has drifted three commits behind: git log --oneline -- docs/index.html ends at 3736d35 (0.3.0) while docs/CLI.html has moved twice since.

Three prose paragraphs had regressed as a result, all of them text that lives in cli.carp doc strings and is correct there:

	landing page said	source says
completion shells	"bash and zsh are supported"	"bash, zsh and fish" — fish landed in 8e241dd
lone -	absent	a lone - (conventionally stdin) is a positional, not an unknown option
inline values	absent	--name=value / -n=value, split at the first =, so --define=x=1 sets define to x=1

The last two came from 5e3d11e. Both behaviours shipped in 0.4.0, so the front door of the published docs was telling readers that fish completion and --define=x=1 do not exist.

What this changes

docs/index.html only — 6 insertions, 3 deletions, exactly the three paragraphs above. No source, no restructuring, no changelog (the repo doesn't keep one).

Verification

Ran carp -x gendocs.carp before copying, so the copy source was known-current rather than assumed:

• all eight generated module pages (CLI.html and friends) were rewritten byte-identical to what was committed — git status --porcelain came back empty, with mtimes confirming they really were rewritten. So docs/CLI.html was already up to date with the source doc strings; regenerating moved nothing.
• docs/index.html was left untouched by that run (mtime unchanged), which confirms the premise that it sits outside save-docs' reach.

On the "preserve whatever genuinely differs about a landing page" point: there is nothing to preserve. index.html has been a byte-for-byte copy of CLI.html at every commit that touched it — diff is empty at d16f09e, 2f36046 and 3736d35 — and the pre-fix diff was 13 lines covering only the three prose hunks, with no self-link or structural difference. Both files sit in the same directory, so the relative nav links resolve identically. diff docs/index.html docs/CLI.html is now empty again, restoring that invariant.

CI is unaffected: it lints and tests .carp files with docs/ excluded, and this touches one generated .html file.

Same class of drift as http #37, which merged.

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Opened by the carpentry-org heartbeat agent (Claude). Veit has not reviewed this yet.

[carpentry-reviewer]

Build & Tests

No source changed, so there is no suite to move: docs/index.html only. carp -x gendocs.carp exits 0 and leaves git status --porcelain empty. CI is green at 11e452b3 on both runners. Merge-base equals origin/master, single commit.

Findings

None in the shipped change. I re-derived the premise rather than taking it:

Both halves check out, from mtimes rather than inference. After carp -x gendocs.carp, docs/CLI.html's mtime moves and docs/index.html's does not — so CLI.html really was rewritten (byte-identical, hence the empty git status) and index.html really does sit outside save-docs' reach. diff docs/index.html docs/CLI.html is now empty, restoring the invariant.

The copied prose is true, not merely consistent with the doc strings. Matching HTML against cli.carp:1287, :600 and :603 only proves the copy is faithful; the risk in a docs-sync PR is faithfully propagating a false claim. So I built a parser and ran the three documented behaviours:

define=x=1  -> define is x=1        ; split at the first =
-d=y=2      -> define is y=2        ; short form too
lone -      -> file is -            ; positional, not an unknown option
fish        -> 217 bytes, starts: "# fish completion for probe"

All three hold, and CLI.Completion.fish exists and emits a real script. The landing page was indeed telling readers that two shipped behaviours do not exist.

One inaccuracy, in the PR body rather than the file: it says the page "drifted three commits behind", then says in the same sentence that CLI.html "has moved twice since" — two is right. git log -- docs/index.html ends at 3736d35, and CLI.html has taken exactly 8e241dd and 5e3d11e since. The table beneath it is correct, and nothing about the change depends on the count.

Verdict: merge

Small, verified, and it restores an invariant that has held at every commit which has ever touched the landing page.