Top-level `agentctx --help` sends users to the docs URL for per-command help, but every command already supports `--help`

[Deepam02]

Problem

The top-level help text tells the user that per-command help lives in the docs, implying there is no built-in way to get it:

• File / line: packages/agentctx/src/cli/main.ts:38-39

  Run any command with --help semantics via the docs:
    https://github.com/agentctxhq/agentctx`;

But every user-facing command already accepts --help and prints its own usage block:

• packages/agentctx/src/cli/init.ts:27
• packages/agentctx/src/cli/uninstall.ts:22
• packages/agentctx/src/cli/status.ts:31
• packages/agentctx/src/cli/search.ts:27
• packages/agentctx/src/cli/show.ts:22
• packages/agentctx/src/cli/export.ts:39
• packages/agentctx/src/cli/profile-cmd.ts:30
• packages/agentctx/src/cli/config-cmd.ts:41
• packages/agentctx/src/cli/reset.ts:23
• packages/agentctx/src/cli/sync.ts:25

So agentctx search --help, agentctx export --help, etc. all work today, yet the top-level --help footer never mentions this and instead points only to a GitHub URL. A first-time user reading agentctx --help is steered away from a feature that already exists.

What done looks like

• The footer in HELP (cli/main.ts) advertises the working local help, e.g. Run \agentctx --help` for command-specific options.` (the docs link can stay as an additional reference).
• Wording matches reality: per-command --help is the primary discovery path, the docs URL is secondary.
• No behavior change to the commands themselves — this is a help-text fix only.