- linear-range → also responds to range
- attribute-picker → also responds to attribute

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

BuildAliasHelpMarkdown now appends an embedded Help/<alias>.md if
one exists, so any clet can have rich examples by adding a file.

Add Help/linear-range.md with examples for single, multi, and
range modes, range kinds, and layout options.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

- Multi example uses --options instead of positional args (matches
  how --mode is passed)
- Add numeric range example: seq 0 0.1 10.0 piped as positional
  args, with PowerShell equivalent
- Use short alias (range) consistently in examples

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

- clet help --cat [alias] renders help to stdout as ANSI text
- clet help range --cat works too (flag order doesn't matter)
- clet range help, clet range --help, clet range -h all dispatch
  to the help viewer for that alias
- clet range help --cat combines both: renders help to stdout

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Help pages are now interlinked:
- The overview's Available Clets table links each primary alias
  to its help page via clet:help:<alias> links
- Each clet's help page has a "Back to overview" link at the bottom

Uses a LinkResolver callback on CletRunOptions. DispatchHelp sets
it to a closure that builds help content on demand. MarkdownClet's
LinkClicked handler checks the resolver before falling through to
the default SurfaceOnly behavior.

Clicking a clet name in `clet help` navigates to that clet's help
in-place. Clicking "Back to overview" returns. No process restart,
no temp files — content is swapped in the same viewer session.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Backticks inside link text ([`select`](url)) confused the markdown
parser — rendered as literal backtick-quoted text instead of a
clickable link. Use plain text in link labels instead.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Links inside table cells aren't clickable (gui-cs/Terminal.Gui#5227).
Revert table aliases to plain backtick text and add a "Click for
details:" line after the table with working links to each clet's
help page.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Every clet now has a Help/<alias>.md with usage examples and
sample JSON output. Shown automatically by `clet help <alias>`
or `clet <alias> --help`.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

clet help (and clet help help) now shows examples for navigating
help: --cat, per-clet help, and the equivalent alias-first forms.
Help examples are appended to the overview page.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Add [Help on help](clet:help:help) link in the overview after the
Usage summary. Clicking it navigates to a dedicated help page with
examples. No longer appended to the bottom of every overview render.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Replace ~80 lines of help special-casing in CommandLineRoot with
a proper HelpClet registered in BuiltInClets.

HelpClet:
- Registered as a viewer clet with alias "help"
- AcceptsPositionalArgs (the alias to show help for)
- Builds help content dynamically from the registry
- Handles inter-page navigation via clet:help: links internally
- Handles --cat internally (renders to stdout, returns Ok)
- Has its own Markdown viewer with status bar

CommandLineRoot changes:
- Removed case "help:" block (falls through to DispatchAlias)
- Removed DispatchHelp and BuildHelpContent methods
- clet <alias> help rewrites args as clet help <alias> and re-dispatches
- Removed LinkResolver from CletRunOptions (no longer needed)

AliasDispatcher:
- --cat path now falls through to RunAsync when no static content is
  resolved, so clets that build content dynamically can handle --cat

Closes #105

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

clet:help:help was matching the null-or-help case and returning
the overview. Now alias "help" has its own branch that builds the
help-on-help page with examples from Help/help.md.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

1. Stack overflow on `clet help help`: the alias redirect in
   DispatchAlias now skips when alias is already "help", preventing
   infinite ["help","help"] → ["help","help"] recursion.

2. Unknown alias prints error instead of opening TUI: `clet help xyz`
   now returns an error with "Unknown alias" message and exits 2.

3. --cat output garbled by OSC 8 links: clet:help:* links are
   TUI-only. Strip them (convert [text](clet:help:x) → text) before
   rendering in --cat mode.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

The TerminalEscapeSanitizer was stripping ALL OSC sequences
including OSC 8 (hyperlinks), which are legitimate renderer output
for terminals like Kitty and Ghostty. Now OSC 8 sequences are
passed through while other OSC sequences (window title, clipboard,
etc.) are still stripped.

Reverts the regex link-stripping in HelpClet — with OSC 8
preserved, the links render as clickable hyperlinks in --cat mode.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Help content is authored by us — all links are safe. Clicking a
non-clet: URL in help now opens it via Link.OpenUrl (default
browser) in addition to showing it in the status bar.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Clicking an http:// or https:// link in clet md now opens it in
the default browser via Link.OpenUrl. These are safe — worst case
the user sees a webpage. The URL is still shown in the status bar.

Local .md file navigation (within CWD sandbox) will come when
PR #96 merges.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

1. UnknownAlias test: AliasDispatcher writes "unknown alias"
   (lowercase) — revert the incorrect uppercase change.

2. MdCat_NoContent: stdin is redirected in test runners, so
   MarkdownClet reads empty stdin → "No input received from stdin"
   rather than "No file specified". Accept either message.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>