feat(share): terminal-only sharing, bigger + full-screen — 0.25.0

Scope M12 down to a single shared-terminal mode (D23, amends D16):
- Share page rewritten terminal-only: host shares their PTY/shell; guest watches
  and may type only if the host ticks "Allow the guest to type" (read-only
  otherwise — the D9 consent exception). Terminal is larger; either side can pop
  it full-screen (Esc to exit).
- Removed the read-only stats view + HTTP server (core/share.py) and the
  `rigdoctor share serve` CLI; deleted their tests.
- Docs: D23 added; SPEC/MODULES/ROADMAP updated (M12 → done, terminal-only).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/SPEC.md

@@ -144,15 +144,13 @@ bundles with descriptions and the exact packages each needs → resolve & instal
 mode. Delivered with the user-local install (and the optional `.deb`) (D8). Module
 list/bundling is final per D14.
 
-### M12 — Session sharing / remote assist (D16)
-Lets a user (A) grant a helper (B) inspection access, as an escalating, consent-driven
-ladder: (1) **diagnostic bundle export** (inventory + recent capture log + report, one-way);
-(2) **live read-only view** of the dashboard + logs over a user-chosen tunnel
-(Tailscale/cloudflared/SSH — no RigDoctor-hosted relay); (3) **gated interactive terminal**
-wrapping an existing tool (tmate/sshx), read-only by default, read-write only on explicit
-consent. Per-session consent, ephemeral revocable tokens, permission escalation (view ≠
-shell), and a session audit log. Tier 3 is a deliberate, consent-gated exception to the
-read-only stance (D9). Built in Phase 6.
+### M12 — Session sharing / remote assist (D16, scoped to terminal-only by D23)
+Lets a user (A) grant a helper (B) a **shared terminal** over the relay: A shares a real PTY
+running their shell; B watches live and may type **only if A allows it** (otherwise read-only)
+— a deliberate, consent-gated exception to the read-only stance (D9). A reads along and can
+type too (e.g. a sudo password, which stays local and is never sent to B). Account-gated by the
+Gitea token; per-session share code. The shared terminal preserves colors/theming and can be
+viewed full-screen. *(The earlier read-only stats view / bundle export were dropped — D23.)*
 
 ## 5. Non-functional requirements
 - **Zero hard deps for the core/CLI/daemon** — Python stdlib + tools already present. **Qt