PHP shims: derive paths from __DIR__ (PHP-FPM runs as caddy user)

BirdNET-Pi's installer runs PHP-FPM as the caddy user, so getenv('HOME')
resolves to /var/lib/caddy - not the install user's home. Every path
constructed from getenv('HOME') was broken on first install.

PHP resolves __DIR__ through the install_services.sh symlink to the
realpath ($HOME/BirdNET-Pi/avian/api), so dirname(__DIR__, 2) = the
BirdNET-Pi install root and dirname(__DIR__, 3) = the user's home.
Works under any username because nothing is hardcoded.

Also fixed birdnet-api.php's DB_PATH which walked one level too far
(used , 3) - the BirdNET-Pi root is , 2).

avian/api/birdnet-api.php

@@ -18,18 +18,14 @@ declare(strict_types=1);
 header('Content-Type: application/json; charset=utf-8');
 header('Cache-Control: public, max-age=30');
 
-// SCRIPT_FILENAME on the Pi resolves through the symlink to
+// PHP resolves __DIR__ through symlinks to the realpath. This script
-// $HOME/BirdNET-Pi/avian/api/birdnet-api.php - walk three dirs up to
+// lives at $HOME/BirdNET-Pi/avian/api/birdnet-api.php (served via the
-// reach the install root, then point at scripts/birds.db. Lets a Pi
+// ${EXTRACTED}/avian symlink). dirname(..., 2) walks to the BirdNET-Pi
-// installed under any username (the BirdNET-Pi installer uses $USER,
+// install root. Works under any username because we never bake the
-// not a fixed name) work without editing this file.
+// home directory in. getenv('HOME') would resolve to /var/lib/caddy
-$DB_PATH = dirname(__DIR__, 3) . '/scripts/birds.db';
+// under PHP-FPM (BirdNET-Pi runs it as the caddy user), so it can't
-// Fallback if the symlink layout ever changes - keeps the most common
+// be relied on.
-// install path working even if SCRIPT_FILENAME oddities trip __DIR__.
+$DB_PATH = dirname(__DIR__, 2) . '/scripts/birds.db';
-if (!file_exists($DB_PATH)) {
-    $alt = getenv('HOME') . '/BirdNET-Pi/scripts/birds.db';
-    if (file_exists($alt)) $DB_PATH = $alt;
-}
 
 if (!file_exists($DB_PATH)) {
     http_response_code(503);

avian/api/cutout.php

@@ -54,7 +54,7 @@ if (is_file($cutout) && filesize($cutout) > 1024) {
 }
 
 // 3. Dynamic cache from a previous Wikipedia + rembg run.
-$cacheDir = getenv('HOME') . '/BirdSongs/Extracted/cutouts';
+$cacheDir = dirname(__DIR__, 3) . '/BirdSongs/Extracted/cutouts';
 $cachePath = "$cacheDir/$slug.png";
 if (is_file($cachePath) && filesize($cachePath) > 1024) {
     serve_png($cachePath);

avian/api/recording.php

@@ -32,7 +32,7 @@ if ($sci !== '' && !preg_match('/^[A-Za-z]{2,40}(?:[ ][a-z]{2,40}){1,3}$/', $sci
     exit;
 }
 
-$BY_DATE = getenv('HOME') . '/BirdSongs/Extracted/By_Date';
+$BY_DATE = dirname(__DIR__, 3) . '/BirdSongs/Extracted/By_Date';
 
 // ---- Direct-by-file lookup ----
 // Used by the atlas detail modal to play any past recording.
@@ -96,7 +96,7 @@ if ($file !== '') {
 // ---- Resolve scientific name → common name (with underscores) ----
 function resolve_common(string $sci): ?string {
     // Try birds.json first (preferred - has clean sci/com pairs).
-    foreach ([getenv('HOME') . '/BirdNET-Pi/scripts/birds.json'] as $f) {
+    foreach ([dirname(__DIR__, 3) . '/BirdNET-Pi/scripts/birds.json'] as $f) {
         if (is_readable($f)) {
             $list = json_decode((string)file_get_contents($f), true);
             if (is_array($list)) {
@@ -112,7 +112,7 @@ function resolve_common(string $sci): ?string {
         }
     }
     // Fallback: labels.txt has "<sci>_<com>" or "<sci>, <com>" per line.
-    $labels = getenv('HOME') . '/BirdNET-Pi/model/labels.txt';
+    $labels = dirname(__DIR__, 3) . '/BirdNET-Pi/model/labels.txt';
     if (is_readable($labels)) {
         foreach (file($labels, FILE_IGNORE_NEW_LINES) as $line) {
             if (strpos($line, '_') !== false) {

avian/api/spectrogram.php

@@ -31,7 +31,7 @@ if ($sci !== '' && !preg_match('/^[A-Za-z]{2,40}(?:[ ][a-z]{2,40}){1,3}$/', $sci
     exit;
 }
 
-$BY_DATE = getenv('HOME') . '/BirdSongs/Extracted/By_Date';
+$BY_DATE = dirname(__DIR__, 3) . '/BirdSongs/Extracted/By_Date';
 
 // ---- Direct-by-file lookup ----
 // BirdNET-Pi writes <base>.mp3 and <base>.png next to each other under
@@ -93,7 +93,7 @@ if ($file !== '') {
 }
 
 function resolve_common(string $sci): ?string {
-    $f = getenv('HOME') . '/BirdNET-Pi/scripts/birds.json';
+    $f = dirname(__DIR__, 3) . '/BirdNET-Pi/scripts/birds.json';
     if (is_readable($f)) {
         $list = json_decode((string)file_get_contents($f), true);
         if (is_array($list)) {
@@ -107,7 +107,7 @@ function resolve_common(string $sci): ?string {
             }
         }
     }
-    $labels = getenv('HOME') . '/BirdNET-Pi/model/labels.txt';
+    $labels = dirname(__DIR__, 3) . '/BirdNET-Pi/model/labels.txt';
     if (is_readable($labels)) {
         foreach (file($labels, FILE_IGNORE_NEW_LINES) as $line) {
             if (strpos($line, '_') !== false) {