assets: add GoSentry wordmark logo (clock-dial variant)

Recommended variant from gosentry-logo.html: Space Grotesk SemiBold with
an amber "G", a clock-dial "o" (ring + hands), and petrol "Sentry". Ships
self-contained SVGs (glyphs outlined to paths, no font dependency) in
light/dark/mono plus transparent PNGs at 256-2048px, with a README and the
gen_logo.py/raster.py generators for reproducibility.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

assets/logo/raster.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+"""Rasterize the GoSentry wordmark to PNG at several widths, reusing the
+same font outlines + dial geometry as gen_logo.py (no SVG rasterizer needed)."""
+import os, math
+import matplotlib
+matplotlib.use("Agg")
+import matplotlib.pyplot as plt
+from matplotlib.path import Path
+from matplotlib.patches import PathPatch, Circle
+from matplotlib.lines import Line2D
+from fontTools.ttLib import TTFont
+from fontTools.pens.basePen import BasePen
+from fontTools.pens.boundsPen import BoundsPen
+from fontTools.pens.transformPen import TransformPen
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+OUT  = os.path.join(HERE, "out"); os.makedirs(OUT, exist_ok=True)
+AMBER, PETROL, WHITE = "#F7A80C", "#0A4A58", "#FFFFFF"
+LS = -30
+
+f = TTFont(os.path.join(HERE, "SpaceGrotesk-600.ttf"))
+cmap, hmtx, gs = f.getBestCmap(), f["hmtx"], f.getGlyphSet()
+
+class MplPen(BasePen):
+    def __init__(self, glyphSet):
+        super().__init__(glyphSet); self.v=[]; self.c=[]
+    def _moveTo(self,p): self.v.append(p); self.c.append(Path.MOVETO)
+    def _lineTo(self,p): self.v.append(p); self.c.append(Path.LINETO)
+    def _curveToOne(self,p1,p2,p3):
+        self.v += [p1,p2,p3]; self.c += [Path.CURVE4]*3
+    def _qCurveToOne(self,p1,p2):
+        self.v += [p1,p2]; self.c += [Path.CURVE3]*2
+    def _closePath(self):
+        self.v.append((0,0)); self.c.append(Path.CLOSEPOLY)
+
+def glyph_mplpath(ch, dx):
+    pen = MplPen(gs)
+    gs[cmap[ord(ch)]].draw(TransformPen(pen,(1,0,0,1,dx,0)))
+    return Path(pen.v, pen.c), hmtx[cmap[ord(ch)]][0]
+
+# layout
+x=0.0
+paths_amber=[]; paths_petrol=[]
+p,adv = glyph_mplpath("G",x); paths_amber.append(p); x+=adv+LS
+og=cmap[ord("o")]; bp=BoundsPen(gs); gs[og].draw(bp)
+oxmin,oymin,oxmax,oymax=bp.bounds; o_adv=hmtx[og][0]
+cx=x+(oxmin+oxmax)/2; cy=(oymin+oymax)/2
+R=((oxmax-oxmin)+(oymax-oymin))/4
+x+=o_adv+LS
+for ch in "Sentry":
+    p,adv=glyph_mplpath(ch,x); paths_petrol.append(p); x+=adv+LS
+x-=LS
+
+SW=R*0.30; Rmid=R-SW/2; HW=R*0.21
+hour_len=R*0.54; min_len=R*0.46; ang=math.radians(62)
+mx=cx+min_len*math.sin(ang); my=cy+min_len*math.cos(ang); cap=R*0.14
+
+# bounds
+allb=BoundsPen(gs); gs[cmap[ord('G')]].draw(allb)
+xx=hmtx[cmap[ord('G')]][0]+LS+o_adv+LS
+for ch in "Sentry":
+    gs[cmap[ord(ch)]].draw(TransformPen(allb,(1,0,0,1,xx,0))); xx+=hmtx[cmap[ord(ch)]][0]+LS
+bx0,by0,bx1,by1=allb.bounds
+bx0=min(bx0,cx-R-SW/2); bx1=max(bx1,cx+R+SW/2)
+by0=min(by0,cy-R-SW/2); by1=max(by1,cy+R+SW/2)
+PAD=60
+X0,X1=bx0-PAD,bx1+PAD; Y0,Y1=by0-PAD,by1+PAD
+W=X1-X0; H=Y1-Y0
+
+def render(path_png, width_px, sentry_color, bg=None, mono=False):
+    dpi=100
+    fw=width_px/dpi; fh=fw*H/W
+    fig=plt.figure(figsize=(fw,fh),dpi=dpi)
+    ax=fig.add_axes([0,0,1,1]); ax.set_xlim(X0,X1); ax.set_ylim(Y0,Y1)
+    ax.set_aspect('equal'); ax.axis('off')
+    if bg: fig.patch.set_facecolor(bg); ax.set_facecolor(bg)
+    else:  fig.patch.set_alpha(0)
+    amberc = sentry_color if mono else AMBER
+    for p in paths_amber: ax.add_patch(PathPatch(p,facecolor=amberc,edgecolor='none',antialiased=True))
+    for p in paths_petrol: ax.add_patch(PathPatch(p,facecolor=sentry_color,edgecolor='none',antialiased=True))
+    pt_per_unit = fw/W*72
+    ax.add_patch(Circle((cx,cy),Rmid,fill=False,edgecolor=amberc,linewidth=SW*pt_per_unit))
+    for (ex,ey) in [(cx,cy+hour_len),(mx,my)]:
+        ax.add_line(Line2D([cx,ex],[cy,ey],color=amberc,linewidth=HW*pt_per_unit,
+                    solid_capstyle='round'))
+    ax.add_patch(Circle((cx,cy),cap,facecolor=amberc,edgecolor='none'))
+    fig.savefig(path_png,dpi=dpi,transparent=(bg is None))
+    plt.close(fig)
+    print("wrote",os.path.basename(path_png))
+
+for w in (256,512,1024,2048):
+    render(os.path.join(OUT,f"gosentry-logo-{w}.png"),w,PETROL)
+    render(os.path.join(OUT,f"gosentry-logo-dark-{w}.png"),w,WHITE)
+render(os.path.join(OUT,"gosentry-logo-onlight-1024.png"),1024,PETROL,bg="#FFFFFF")
+render(os.path.join(OUT,"gosentry-logo-ondark-1024.png"),1024,WHITE,bg="#04262E")
+render(os.path.join(OUT,"gosentry-logo-mono-1024.png"),1024,PETROL,mono=True)
+print(f"aspect {W:.0f}x{H:.0f}")