Generated CLI reference and man pages from cobra #56

Why

docs/cli.md is hand-written and already 470 lines; every new flag needs a matching edit and nothing checks they agree. cobra can generate Markdown and man pages from the command tree, which also gives the deb/rpm/Homebrew packages something to install under man/.

What

• A hidden apic docs --format markdown|man --out <dir> command using github.com/spf13/cobra/doc (a separate module from cobra; measure the binary and, if it is too heavy, keep the generator under scripts/ instead).
• docs/cli.md keeps its hand-written top (targets, exit codes, JSON shapes) and gains a generated "Commands and flags" section produced by task docs:cli; CI fails if the committed file is stale (task docs:cli && git diff --exit-code).
• goreleaser ships man/apic*.1 in the archives and the nfpm packages install them; the Homebrew formula installs them and the completions.
• Housekeeping while here: internal/cli/inspect.go holds list, describe, curl, env, session and validate but there is no inspect command; split or rename so the file name matches the contents (AGENTS.md layout entry updated).

Where

internal/cli/docs.go, internal/cli/root.go, Taskfile.yml, .github/workflows/ci.yml, .goreleaser.yaml, docs/cli.md.

Docs

docs/cli.md (structure), AGENTS.md ("New commands need…" rule mentions the generator), CONTRIBUTING.md.

Tests

A test that the generated Markdown for run contains every flag the command registers; the CI staleness check.