fix: inject <base href> from base_path config; fix relative asset/nav links; add README

http/handlers.c

@@ -117,7 +117,7 @@ void handle_series_show(int fd, const char *qs) {
     buf_free(&inl);
 
     free(sid); free(title_raw); free(cover_raw); free(json);
-    send_page(fd, "Series", &b, "/series_show.js");
+    send_page(fd, "Series", &b, "series_show.js");
     buf_free(&b);
 }
 
@@ -226,7 +226,7 @@ void handle_downloads(int fd) {
                 "<button class='btn btn-r' onclick=cleanPartials()>clean partial files</button>"
                 "</div>"
                 "<div id=dl-table><p style='color:var(--dim)'>loading...</p></div>");
-    send_page(fd, "Downloads", &b, "/downloads.js");
+    send_page(fd, "Downloads", &b, "downloads.js");
     buf_free(&b);
 }
 

http/http.c

@@ -77,8 +77,19 @@ int parse_request(int fd, Req *req) {
 void send_page(int fd, const char *title, Buf *body, const char *script_src) {
     Buf page; buf_init(&page);
     buf_str(&page, "HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\n\r\n");
+    /* inject <base href> so relative assets resolve correctly at any sub-path */
     const char *ph = strstr(g_header, "{{TITLE}}");
-    if (ph) {
+    const char *head_end = strstr(g_header, "</head>");
+    if (ph && head_end && head_end > ph) {
+        /* write up to </head>, inject base tag, then rest of header */
+        buf_append(&page, g_header, ph - g_header);
+        buf_str(&page, title);
+        const char *after_title = ph + 9;
+        buf_append(&page, after_title, head_end - after_title);
+        if (g_cfg.base_path[0])
+            buf_fmt(&page, "<base href=\"%s/\">", g_cfg.base_path);
+        buf_str(&page, head_end);
+    } else if (ph) {
         buf_append(&page, g_header, ph - g_header);
         buf_str(&page, title);
         buf_str(&page, ph + 9);