feat: make sidebar CI and review glyphs configurable via .env

[ubuntudroid]

Summary

Lets users override every sidebar glyph via the plugin's existing .env mechanism (gci_load_env), defaulting to the current emoji:

• CI dot: GITLAB_CI_ICON_OK / _FAIL / _RUN / _NONE (defaults 🟢 🔴 🟡 ⚪)
• Review badge / My-MRs glyphs: GITLAB_CI_ICON_CONFLICT / _CHANGES / _APPROVED / _DRAFT / _AWAITING (defaults ⚠️ 💬 ✅ 📝 👀)

Emoji stay the default so plain terminals keep working; the README shows a commented Nerd Font preset (needs a Nerd-patched font, else tofu). A var that is set but empty hides the glyph — e.g. GITLAB_CI_ICON_NONE= shows no dot for "no pipeline" — which is why the code uses ${VAR-default} rather than ${VAR:-default}.

Details worth calling out:

• gci_strip_ci_prefix is driven by the same configured values, and additionally keeps hunting the emoji defaults — labels decorated before an icon-config change still strip instead of accumulating a prefix per poll tick. Empty patterns are skipped ("" would match anything and corrupt labels).
• gci_review_badge_glyph now delegates to gci_review_glyph, so badge and My-MRs pane can't drift apart.
• The "supported remote, no pipeline" path in poller-ctl.sh hardcoded ⚪; it now routes through gci_status_emoji so the _NONE override applies there too.
• Version left untouched for the maintainer to bump.

Heads-up: a separate PR adding a merged state + 🔀 badge is coming soon and touches the same glyph functions; whichever lands second just applies the same ${VAR-default} pattern to the merged glyph — trivial rebase.

Test plan

• bash test.sh — 119 checks green. New coverage: per-state overrides, badge filtering with overrides, empty-override hiding, strip round-trips built the way poll_once builds labels, default-emoji-still-strips migration case, and the empty-pattern strip guard (each new test was watched failing first).
• Verified live in herdr with a Nerd Font .env preset: sidebar labels render the monochrome glyphs, GITLAB_CI_ICON_NONE= hides the "no pipeline" dot, and poller stop restores labels cleanly.

🤖 Generated with Claude Code