fix(docs): copy-pasteable CLI commands, no credential-less search bar, an env table that matches the launcher

[latekvo]

Three defects found while reviewing the docs site, each fixed in its own commit.

argent <subcommand> cannot be copied out of the CLI table

Every command cell in docs/reference/cli.mdx separated the two words with
U+00A0 instead of a space:

$ sed -n '11p' packages/docs/docs/reference/cli.mdx | head -c 40 | od -An -tx1 -c
  7c  20  60  61  72  67  65  6e  74  c2  a0  69  6e  69  74  60
   |       `   a   r   g   e   n   t      **   i   n   i   t   `

The character survives the build - 16 <code>argent\xa0...</code> in the built
HTML and 16 in llms-full.txt - so a reader who copies argent init and runs
it gets argent init: command not found, and so does an agent reading the
llms files.

19 occurrences replaced with ordinary spaces; nothing else in the file changed
(old.replace(' ', ' ') == new). A Repo Hygiene step now fails on the
next one, since the table grew three more between this page landing and today.
The pattern is spelled as bytes rather than grep -P '\x{00a0}' so it does not
depend on git being built with PCRE; it was verified to exit 1 on the fixed tree
and 0 with a single NBSP restored.

The published site shipped a search bar wired to placeholder credentials

themeConfig.algolia fell back to the literal strings ARGENT_DOCSEARCH_APP_ID
and ARGENT_DOCSEARCH_API_KEY, and docs-publish.yml runs npm run build with
no env: block, so those placeholders were baked into every published page. The
navbarSearchWrapper CSS rule hid the button only - useDocSearchKeyboardEvents
still bound Cmd+K, the modal still opened, its queries went to
https://argent_docsearch_app_id-dsn.algolia.net/ (ERR_NAME_NOT_RESOLVED) and
the reader was told No results found for "flow". The build also emitted a
/search page (with <title>[object Object]</title>, from the shared theme),
listed it in sitemap.xml, and added a preconnect to the same dead host.

The algolia block is now built only when ALGOLIA_APP_ID and
ALGOLIA_API_KEY are both set. Without them the classic preset never loads
@docusaurus/theme-search-algolia (it keys off the block's presence), so there
is no /search route, no preconnect and no placeholder anywhere in build/;
the navbar is told not to mount the bar via the shared theme's own
isAlgoliaActive prop, so Cmd+K is never bound. The shared theme's navbar
imports @docusaurus/theme-search-algolia/client whether search is on or not,
and that module imports @theme/SearchTranslations - normally owned by the
search theme - so a small plugin supplies that one alias while the theme is
absent.

Verified by building both ways: without credentials the output has no
DocSearch markup, no preconnect, no /search and no search entry in the
sitemap; with ALGOLIA_APP_ID=TESTAPPID ALGOLIA_API_KEY=testapikey the bar,
the /search page and preconnect href="https://TESTAPPID-dsn.algolia.net"
all come back.

An exported ARGENT_HOST broke every tool call

buildToolsServerEnv always overwrites ARGENT_PORT but sets ARGENT_HOST
only when the caller passes one, and the spawned child inherits the caller's
environment. The auto-spawn path (MCP, argent run) never passed one, while
recording host: "127.0.0.1" in the state file, health-checking 127.0.0.1
and returning http://127.0.0.1:<port>:

$ HOME=$SB/home2 ARGENT_HOST=::1 argent tools
connect ECONNREFUSED 127.0.0.1:50333
# state file: "host": "127.0.0.1"
# server log: GET http://[::1]:50333/tools

Every call failed, and each run left an unreachable server behind.
argent server start was never affected - both its foreground and detached
paths pass an explicit --host, defaulting to 127.0.0.1.

The auto-spawn path now passes the host it already records. The new test drives
ensureToolsServer with ARGENT_HOST=::1 exported and asserts the returned URL
answers; removing the one-line fix turns it red (expected false to be true on
the health check). test/setup/clear-argent-env.ts documented this bug as the
reason it exists, so its rationale is updated to the general one that remains.

The same asymmetry made three rows of the tool-server env table wrong: both
launchers always set ARGENT_PORT, ARGENT_HOST and
ARGENT_IDLE_TIMEOUT_MINUTES, so exporting any of them reaches nothing, and the
auto-spawn path's idle timeout is 30 minutes rather than the documented 0. The
rows now name the argent server start flag that moves each value and what a
server started on demand uses instead.

Checks run

npx tsc --build, npm run lint, npx prettier --check ., npm run knip
(exit 0), packages/docs npm run typecheck + npm run build (both with and
without credentials), and the @argent/tools-client (192) and @argent/cli
(472) suites. packages/argent has one unrelated pre-existing flake,
dispatcher > forwards SIGTERM to the child binary, which passes in isolation.