build: 0.8.10 — SUFeedURL -> xplor.sh (no-cache Cloudflare feed)

Points new builds at the Cloudflare-served xplor.sh appcast (no-cache) so update
checks propagate instantly + accurately. The legacy GitHub Pages feed stays for
<=0.8.9 installs. No code change vs 0.8.9 beyond the feed URL + version bump.

feat(update): cross-platform Updates controls (unify endpoints + Win/…

…Linux)

- UpdateChecker (Win/Linux): AutoCheckEnabled/SetAutoCheck/CheckNow, persisted to
  ~/.xplorer/update_prefs.json; Start() honors the pref; current version set at
  construction; auto_check in StatusDict
- gateway: unify /api/update/sparkle -> /api/update/controls{,/auto-check,/check},
  routing macOS->Sparkle and Win/Linux->UpdateChecker (returns 'supported')
- settings.js: call /api/update/controls, gate on 'supported'
The common.js update banner already handles the Win/Linux apply/restart flow.

fix(apply): self-heal IDS_XPLORER_SETTINGS — strip existing before add

The plain idempotent insert is defeated when the message TEXT changes (Xplorer
settings -> Xplor settings): the already-present check misses the old wording and
adds a second copy, so a chromium tree that has an older copy committed in fails
grit with DuplicateKey: IDS_XPLORER_SETTINGS (hit on the Windows build host).
Strip any existing IDS_XPLORER_SETTINGS message(s) before adding one — yields
exactly one regardless of prior wording or tree state. Verified: clean->1,
dup-injected->stripped->1.

release: bump XPLORER_VERSION 0.8.6 -> 0.8.7 (first auto-update-enabl…

…ed release)

fix(build): Windows EnvironmentMap is wstring — convert child env; bu…

…mp v0.8.6

The agent child-env code did `options.environment = <std::map<string,string>>`,
which does NOT compile on Windows: base::EnvironmentMap is map<wstring,wstring> on
Windows (map<string,string> only on POSIX). So grok_native.cc never compiled on
Windows since the scheduled-task/chat env was added — the prior 'Windows builds'
packaged a stale chrome.exe. macOS/Linux were fine (POSIX EnvironmentMap is
string-based), which masked it.

Add ToEnvironmentMap() that builds a platform-correct base::EnvironmentMap
(UTF8ToWide on Windows) and route all 4 options.environment assignments through it
(LaunchGrokStdoutProcess x2 for scheduled-task env; PumpGrokStream x2 for the
per-chat XPLORER_AGENT_ID). +base/environment.h.

Also bumps XPLORER_VERSION 0.8.5 -> 0.8.6 for the release.

fix(sidebar): clipboard works — make side-panel WebView the macOS fir…

…st responder

The real, verified fix. On macOS Cut/Copy/Paste/Select-All are Cocoa selectors
dispatched to the NSWindow first responder, so the side-panel RWHV NSView must
literally BE the first responder. WasShown() only un-hides it (necessary, not
sufficient). CompanionWebView now also drives web_contents()->Focus() via a
deferred+retried RequestFocus once shown/drawn, plus on OnFocus and
OnWebContentsFocused (re-focus on click). Also fixes a delegate clobber:
SetDelegate() now runs AFTER SetOwnedWebContents() (which calls SetDelegate(this)).
Cross-platform safe.

fix(omnibox): blank address bar on the new-tab Grok home, like the NTP

New tabs open the Grok home, which is a real http gateway page, so the address
bar showed http://127.0.0.1:9334/search instead of being blank like a normal
new tab. ChromeLocationBarModelDelegate::ShouldDisplayURL() now returns false
for our gateway home pages (search/companion/welcome) — the same path the NTP
uses — so the omnibox is blank while the page stays http (Grok injectors still
attach).

release: bump version to 0.8.2 (app builder native side panel + canvas)

release: v0.8.0 + refresh bundled companion UI before signing

The build leaves the bundle's companion/ui stale (it persists across builds and
nothing recopies it), so releases were at risk of shipping old sidebar UI.
release_arch.sh now copies the current companion/ui into the app bundle right
after build, before signing. Bump to 0.8.0.

Merge pull request #9 from daniel-farina/branding-phase3

v0.8.0: concurrent agents, kill switch, crash fix, max-turns, model fixes