feat(makie): implement area-elevation-profile (#8638)

## Implementation: `area-elevation-profile` - julia/makie

Implements the **julia/makie** version of `area-elevation-profile`.

**File:** `plots/area-elevation-profile/implementations/julia/makie.jl`

**Parent Issue:** #4578

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/27256310300)*

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Markus Neusinger <2921697+MarkusNeusinger@users.noreply.github.com>

Author: github-actions[bot]

plots/area-elevation-profile/implementations/julia/makie.jl

@@ -0,0 +1,168 @@
+# anyplot.ai
+# area-elevation-profile: Terrain Elevation Profile Along Transect
+# Library: makie 0.22.10 | Julia 1.11.9
+# Quality: 90/100 | Created: 2026-06-10
+
+using CairoMakie
+using Colors
+using Random
+
+Random.seed!(42)
+
+# Theme tokens
+const THEME       = get(ENV, "ANYPLOT_THEME", "light")
+const PAGE_BG     = THEME == "light" ? colorant"#FAF8F1" : colorant"#1A1A17"
+const ELEVATED_BG = THEME == "light" ? colorant"#FFFDF6" : colorant"#242420"
+const INK         = THEME == "light" ? colorant"#1A1A17" : colorant"#F0EFE8"
+const INK_SOFT    = THEME == "light" ? colorant"#4A4A44" : colorant"#B8B7B0"
+const INK_MUTED   = THEME == "light" ? colorant"#6B6A63" : colorant"#A8A79F"
+const FILL_ALPHA  = THEME == "light" ? 0.28f0 : 0.42f0
+
+const IMPRINT_PALETTE = [
+    colorant"#009E73",  # 1 — brand green (first series, always)
+    colorant"#C475FD",  # 2 — lavender
+    colorant"#4467A3",  # 3 — blue
+    colorant"#BD8233",  # 4 — ochre
+    colorant"#AE3030",  # 5 — matte red (semantic: bad/loss)
+    colorant"#2ABCCD",  # 6 — cyan
+    colorant"#954477",  # 7 — rose
+    colorant"#99B314",  # 8 — lime
+]
+
+# Data: Fictional alpine traverse — 80 km route across passes and summits
+wp_dist = [  0.0,  10.0,  18.0,  26.0,  35.0,  45.0,  60.0,  70.0,  80.0]
+wp_elev = [950.0, 1600.0, 2750.0, 2050.0, 3180.0, 2600.0, 2900.0, 2150.0, 1050.0]
+
+n = 320
+distance = collect(range(0.0, 80.0, length=n))
+
+function lerp_elev(d)
+    for i in 2:length(wp_dist)
+        if d <= wp_dist[i]
+            t = (d - wp_dist[i-1]) / (wp_dist[i] - wp_dist[i-1])
+            return wp_elev[i-1] + t * (wp_elev[i] - wp_elev[i-1])
+        end
+    end
+    return wp_elev[end]
+end
+
+elev_base = lerp_elev.(distance)
+
+function gauss_smooth(v, sigma)
+    nv = length(v)
+    ks = round(Int, 3 * sigma)
+    result = similar(v, Float64)
+    for i in 1:nv
+        s = 0.0; w = 0.0
+        for j in max(1, i - ks):min(nv, i + ks)
+            wj = exp(-0.5 * ((j - i) / sigma)^2)
+            s += wj * v[j]; w += wj
+        end
+        result[i] = s / w
+    end
+    return result
+end
+
+# Terrain micro-texture via superimposed sinusoids (no cumulative drift)
+terrain_noise = zeros(n)
+for freq in [4, 9, 17, 29]
+    terrain_noise .+= randn() .* sin.(range(0.0, Float64(freq) * π, length=n) .+ rand() * 2π)
+end
+terrain_noise = gauss_smooth(terrain_noise, 3.0) .* 28.0
+
+elevation = elev_base .+ terrain_noise
+
+# Key landmarks — pairs of (distance_km, label)
+lm_dists   = [  0.0,       18.0,          35.0,          45.0,          60.0,       80.0]
+lm_labels  = ["Trailhead", "First Pass", "Summit Peak", "Col de Neige", "Grand Col", "Trail End"]
+lm_idx     = [argmin(abs.(distance .- d)) for d in lm_dists]
+lm_elevs   = elevation[lm_idx]
+lm_offsets = [180.0, 180.0, 200.0, -230.0, 180.0, 180.0]
+lm_valigns = [:bottom, :bottom, :bottom, :top, :bottom, :bottom]
+lm_haligns = [:left,   :center, :center,  :center,        :center,     :right  ]
+
+const TITLE = "area-elevation-profile · julia · makie · anyplot.ai"
+title_fontsize = 20  # 51 chars < 67 baseline — no scaling needed
+
+# Figure
+fig = Figure(
+    size            = (1600, 900),
+    fontsize        = 14,
+    backgroundcolor = PAGE_BG,
+)
+
+ax = Axis(
+    fig[1, 1];
+    title              = TITLE,
+    titlesize          = title_fontsize,
+    titlecolor         = INK,
+    xlabel             = "Distance (km)",
+    ylabel             = "Elevation (m)",
+    xlabelsize         = 14,
+    ylabelsize         = 14,
+    xlabelcolor        = INK,
+    ylabelcolor        = INK,
+    xticklabelsize     = 12,
+    yticklabelsize     = 12,
+    xticklabelcolor    = INK_SOFT,
+    yticklabelcolor    = INK_SOFT,
+    xtickcolor         = INK_SOFT,
+    ytickcolor         = INK_SOFT,
+    backgroundcolor    = PAGE_BG,
+    topspinevisible    = false,
+    rightspinevisible  = false,
+    leftspinecolor     = INK_SOFT,
+    bottomspinecolor   = INK_SOFT,
+    xgridvisible       = false,
+    ygridcolor         = RGBAf(INK.r, INK.g, INK.b, 0.12),
+    yminorgridvisible  = false,
+    xminorgridvisible  = false,
+    limits             = (0.0, 82.0, 500.0, 3700.0),
+)
+
+# Filled terrain silhouette (Imprint brand green; alpha higher on dark for equal visual weight)
+band!(ax, distance, fill(500.0, n), elevation;
+      color = RGBAf(IMPRINT_PALETTE[1].r, IMPRINT_PALETTE[1].g, IMPRINT_PALETTE[1].b, FILL_ALPHA))
+
+# Profile line
+lines!(ax, distance, elevation;
+       color = IMPRINT_PALETTE[1], linewidth = 2.5)
+
+# Landmark annotations — Summit Peak gets extra emphasis as the highest point
+for i in 1:length(lm_dists)
+    d    = lm_dists[i]
+    name = lm_labels[i]
+    elev = lm_elevs[i]
+    off  = lm_offsets[i]
+    va   = lm_valigns[i]
+
+    is_summit = (name == "Summit Peak")
+    msize     = is_summit ? 13 : 9
+    mstroke   = is_summit ? 2.5f0 : 1.5f0
+
+    # Connector line from terrain point to label position
+    lines!(ax, [d, d], [elev, elev + off];
+           color = RGBAf(INK_MUTED.r, INK_MUTED.g, INK_MUTED.b, 0.5),
+           linewidth = 0.8)
+
+    # Dot marker at elevation (Summit Peak larger for focal hierarchy)
+    scatter!(ax, [d], [elev];
+             color = IMPRINT_PALETTE[1], markersize = msize,
+             strokecolor = PAGE_BG, strokewidth = mstroke)
+
+    # Label: name + elevation; 13 pt for mobile readability
+    text!(ax, d, elev + off;
+          text     = "$(name)\n$(round(Int, elev)) m",
+          align    = (lm_haligns[i], va),
+          fontsize = 13,
+          color    = INK_SOFT)
+end
+
+# Vertical exaggeration note (bottom-right)
+text!(ax, 80.0, 540.0;
+      text     = "VE ≈ 15×",
+      align    = (:right, :bottom),
+      fontsize = 13,
+      color    = INK_MUTED)
+
+save("plot-$(THEME).png", fig; px_per_unit = 2)