Many QoL updates: file preview, objective namespace, brief→context, m…

[andrew-jon-p7a]

…obile, tooling

Filesystem & attachments
- Add /objectives/<id>/ namespace with membership-based ACL (originator + assignee + watchers). Objective-create attachments are mirrored into the namespace by blob-ref — refcounted, no byte duplication; the originator's home copy stays put, so deleting it no longer breaks the objective.
- Add admin-only GET /fs/all flat enumeration of every file across every home, plus an "All files" tab in the FilesPanel for admins.
- New file-preview modal (web): native renderers for image/pdf/ audio/video; lazy markdown via marked + DOMPurify; lazy code view via highlight.js with line numbers + copy. ~60KB lazy chunks; main bundle unchanged. Wired into MessageAttachments and FilesPanel.
- New docs/concepts/files.mdx covering the model end-to-end (paths, two scopes, blob store, attachment lifecycle, grants).

Rename team.brief → team.context
- Field's purpose (team's standing context, complement to directive) reads cleanly alongside the AI-context vocabulary the rest of the system uses. Touched: SDK type + schema, DB column + queries, server validators, wizard prompt, web shell, ac7 team CLI flags (--context, --context-file), docs, config example, all fixtures. No users yet — clean break, no migration code.

Agent tool surface (MCP)
- Drop title from agent-facing broadcast/send/channels_post/ objectives_discuss. Server still uses the field for templated system DMs (session-online, objective-context-reminder).
- Standardize description discipline: every tool description ends with a Returns ... clause; drop redundant authority annotations (visibility gate already implies the perm); drop team.directive embeds (already pinned in the MCP instructions field).
- Update fs/objective tool descriptions for the new namespace; fix stale brief refs in team_update; fs_shared now calls out that namespace files don't appear there (membership not grants).

CLI
- ac7 connect: prompts for the broker URL when neither --url nor AC7_URL is set. Default http://127.0.0.1:8717. Success line now mentions ac7 codex alongside claude-code.
- ac7 claude-code / ac7 codex: fall through to connect when no saved auth, instead of hard-failing.
- Auth config moved from ~/.config/ac7/auth.json to project- scoped ./.ac7/auth.json with git-style walk-up resolution. Same machine can host distinct identities per project.
- Server dbPath resolves relative to the config file, not cwd — fixes the pnpm dev "no team in ./ac7.db" error caused by the wizard and broker disagreeing on cwd.

Web UI
- Inbox: clicking an unread on an objective thread now opens the objective detail (was a silent no-op via selectThread). Auto- read extends to objective-detail views so the inbox row clears on navigation.
- Activity feed: oldest-at-top → newest-at-bottom (chat-style) with sticky-bottom hook + jump-to-latest chevron; HTTP filter defaults off; inspector is resizable on wide viewports via a splitter handle; filter chips collapse into an expandable tray.
- Activity inspector mobile fix: inline position: relative was overriding the overlay media query, eating chat-pane width on phones. Moved to CSS so the breakpoint can override.
- Disconnect banner deferred 3s so tab-resume churn doesn't flash the warning when the WebSocket reconnects within the grace window.
- NavColumn team header shows the viewer's name under the team name (was the team directive — static, uninformative).

Mobile
- Bump input/textarea/select font-size to 16px on touch / narrow viewports to suppress iOS Safari auto-zoom on focus.
- Composer Enter inserts a newline on touch (was send-on-enter); toolbar Send anchored right via margin-left: auto.
- Vite dev server binds on all interfaces so iPhone-via-Tailscale works for cross-device testing.

Dev plumbing
- Vite proxy rules derived from PATHS in the SDK so adding a new broker route requires no proxy edit. /enroll handled with a regex prefix since the bare path is also a SPA route.
- Sticky-bottom + resize-width hooks extracted into reusable lib/use-sticky-bottom.ts / lib/use-resizable-width.ts.

Tests
- New: objective-namespace e2e (mirror, membership ACL, watcher revoke), file-preview dispatch matrix.
- Updated: message-attachments for the chip refactor, briefing/ wizard/test-stores for brief→context, bridge for the dropped directive embed.
- All packages green: server 462, CLI 209, SDK 6, web-shell 168 new + 3 pre-existing failures unrelated to this branch.